RFC5070

Network Working Group R. Danyliw Request for Comments: 5070 CERT Category: Standards Track J. Meijer

                                                             UNINETT
                                                        Y. Demchenko
                                             University of Amsterdam
                                                       December 2007

        The Incident Object Description Exchange Format

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

Abstract

The Incident Object Description Exchange Format (IODEF) defines a data representation that provides a framework for sharing information commonly exchanged by Computer Security Incident Response Teams (CSIRTs) about computer security incidents. This document describes the information model for the IODEF and provides an associated data model specified with XML Schema.

Introduction

Organizations require help from other parties to mitigate malicious activity targeting their network and to gain insight into potential threats. This coordination might entail working with an ISP to filter attack traffic, contacting a remote site to take down a bot- network, or sharing watch-lists of known malicious IP addresses in a consortium.

The Incident Object Description Exchange Format (IODEF) is a format for representing computer security information commonly exchanged between Computer Security Incident Response Teams (CSIRTs). It provides an XML representation for conveying incident information across administrative domains between parties that have an operational responsibility of remediation or a watch-and-warning over a defined constituency. The data model encodes information about hosts, networks, and the services running on these systems; attack methodology and associated forensic evidence; impact of the activity; and limited approaches for documenting workflow.

The overriding purpose of the IODEF is to enhance the operational capabilities of CSIRTs. Community adoption of the IODEF provides an improved ability to resolve incidents and convey situational awareness by simplifying collaboration and data sharing. This structured format provided by the IODEF allows for:

o increased automation in processing of incident data, since the

  resources of security analysts to parse free-form textual
  documents will be reduced;

o decreased effort in normalizing similar data (even when highly

  structured) from different sources; and

o a common format on which to build interoperable tools for incident

  handling and subsequent analysis, specifically when data comes
  from multiple constituencies.

Coordinating with other CSIRTs is not strictly a technical problem. There are numerous procedural, trust, and legal considerations that might prevent an organization from sharing information. The IODEF does not attempt to address them. However, operational implementations of the IODEF will need to consider this broader context.

Sections 3 and 8 specify the IODEF data model with text and an XML schema. The types used by the data model are covered in Section 2. Processing considerations, the handling of extensions, and internationalization issues related to the data model are covered in

Sections 4, 5, and 6, respectively. Examples are listed in Section 7. Section 1 provides the background for the IODEF, and Section 9 documents the security considerations.

Terminology

The key words "MUST," "MUST NOT," "REQUIRED," "SHALL," "SHALL NOT," "SHOULD," "SHOULD NOT," "RECOMMENDED," "MAY," and "OPTIONAL" in this document are to be interpreted as described in RFC2119 [6].

Definitions for some of the common computer security-related terminology used in this document can be found in Section 2 of [16].

Notations

The normative IODEF data model is specified with the text in Section 3 and the XML schema in Section 8. To help in the understanding of the data elements, Section 3 also depicts the underlying information model using Unified Modeling Language (UML). This abstract presentation of the IODEF is not normative.

For clarity in this document, the term "XML document" will be used when referring generically to any instance of an XML document. The term "IODEF document" will be used to refer to specific elements and attributes of the IODEF schema. The terms "class" and "element" will be used interchangeably to reference either the corresponding data element in the information or data models, respectively.

About the IODEF Data Model

The IODEF data model is a data representation that provides a framework for sharing information commonly exchanged by CSIRTs about computer security incidents. A number of considerations were made in the design of the data model.

o The data model serves as a transport format. Therefore, its

  specific representation is not the optimal representation for on-
  disk storage, long-term archiving, or in-memory processing.

o As there is no precise widely agreed upon definition for an

  incident, the data model does not attempt to dictate one through
  its implementation.  Rather, a broad understanding is assumed in
  the IODEF that is flexible enough to encompass most operators.

o Describing an incident for all definitions would require an

  extremely complex data model.  Therefore, the IODEF only intends
  to be a framework to convey commonly exchanged incident
  information.  It ensures that there are ample mechanisms for

  extensibility to support organization-specific information, and
  techniques to reference information kept outside of the explicit
  data model.

o The domain of security analysis is not fully standardized and must

  rely on free-form textual descriptions.  The IODEF attempts to
  strike a balance between supporting this free-form content, while
  still allowing automated processing of incident information.

o The IODEF is only one of several security relevant data

  representations being standardized.  Attempts were made to ensure
  they were complimentary.  The data model of the Intrusion
  Detection Message Exchange Format [17] influenced the design of
  the IODEF.

Further discussion of the desirable properties for the IODEF can be found in the Requirements for the Format for Incident Information Exchange (FINE) [16].

About the IODEF Implementation

The IODEF implementation is specified as an Extensible Markup Language (XML) [1] Schema [2] in Section 8.

Implementing the IODEF in XML provides numerous advantages. Its extensibility makes it ideal for specifying a data encoding framework that supports various character encodings. Likewise, the abundance of related technologies (e.g., XSL, XPath, XML-Signature) makes for simplified manipulation. However, XML is fundamentally a text representation, which makes it inherently inefficient when binary data must be embedded or large volumes of data must be exchanged.

IODEF Data Types

The various data elements of the IODEF data model are typed. This section discusses these data types. When possible, native Schema data types were adopted, but for more complicated formats, regular expressions (see Appendix F of [3]) or external standards were used.

Integers

An integer is represented by the INTEGER data type. Integer data MUST be encoded in Base 10.

The INTEGER data type is implemented as an "xs:integer" [3] in the schema.

Real Numbers

Real (floating-point) attributes are represented by the REAL data type. Real data MUST be encoded in Base 10.

The REAL data type is implemented as an "xs:float" [3] in the schema.

Characters and Strings

A single character is represented by the CHARACTER data type. A character string is represented by the STRING data type. Special characters must be encoded using entity references. See Section 4.1.

The CHARACTER and STRING data types are implement as an "xs:string" [3] in the schema.

Multilingual Strings

STRING data that represents multi-character attributes in a language different than the default encoding of the document is of the ML_STRING data type.

The ML_STRING data type is implemented as an "iodef:MLStringType" in the schema.

Bytes

A binary octet is represented by the BYTE data type. A sequence of binary octets is represented by the BYTE[] data type. These octets are encoded using base64.

The BYTE data type is implemented as an "xs:base64Binary" [3] in the schema.

Hexadecimal Bytes

A binary octet is represented by the HEXBIN (and HEXBIN[]) data type. This octet is encoded as a character tuple consisting of two hexadecimal digits.

The HEXBIN data type is implemented as an "xs:hexBinary" [3] in the schema.

Enumerated Types

Enumerated types are represented by the ENUM data type, and consist of an ordered list of acceptable values. Each value has a representative keyword. Within the IODEF schema, the enumerated type keywords are used as attribute values.

The ENUM data type is implemented as a series of "xs:NMTOKEN" in the schema.

Date-Time Strings

Date-time strings are represented by the DATETIME data type. Each date-time string identifies a particular instant in time; ranges are not supported.

Date-time strings are formatted according to a subset of ISO 8601: 2000 [13] documented in RFC 3339 [12].

The DATETIME data type is implemented as an "xs:dateTime" [3] in the schema.

Timezone String

A timezone offset from UTC is represented by the TIMEZONE data type. It is formatted according to the following regular expression: "Z|[\+\-](0[0-9]|1[0-4]):[0-5][0-9]".

The TIMEZONE data type is implemented as an "xs:string" with a regular expression constraint in the schema. This regular expression is identical to the timezone representation implemented in an "xs: dateTime".

2.10. Port Lists

A list of network ports are represented by the PORTLIST data type. A PORTLIST consists of a comma-separated list of numbers and ranges (N-M means ports N through M, inclusive). It is formatted according to the following regular expression: "\d+(\-\d+)?(,\d+(\-\d+)?)*". For example, "2,5-15,30,32,40-50,55-60".

The PORTLIST data type is implemented as an "xs:string" with a regular expression constraint in the schema.

2.11. Postal Address

A postal address is represented by the POSTAL data type. This data type is an ML_STRING whose format is documented in Section 2.23 of RFC 4519 [10]. It defines a postal address as a free-form multi-line string separated by the "$" character.

The POSTAL data type is implemented as an "xs:string" in the schema.

2.12. Person or Organization

The name of an individual or organization is represented by the NAME data type. This data type is an ML_STRING whose format is documented in Section 2.3 of RFC 4519 [10].

The NAME data type is implemented as an "xs:string" in the schema.

2.13. Telephone and Fax Numbers

A telephone or fax number is represented by the PHONE data type. The format of the PHONE data type is documented in Section 2.35 of RFC 4519 [10].

The PHONE data type is implemented as an "xs:string" in the schema.

2.14. Email String

An email address is represented by the EMAIL data type. The format of the EMAIL data type is documented in Section 3.4.1 RFC 2822 [11]

The EMAIL data type is implemented as an "xs:string" in the schema.

2.15. Uniform Resource Locator strings

A uniform resource locator (URL) is represented by the URL data type. The format of the URL data type is documented in RFC 2396 [8].

The URL data type is implemented as an "xs:anyURI" in the schema.

The IODEF Data Model

In this section, the individual components of the IODEF data model will be discussed in detail. For each class, the semantics will be described and the relationship with other classes will be depicted with UML. When necessary, specific comments will be made about corresponding definition in the schema in Section 8

IODEF-Document Class

The IODEF-Document class is the top level class in the IODEF data model. All IODEF documents are an instance of this class.

+-----------------+ | IODEF-Document | +-----------------+ | STRING version |<>--{1..*}--[ Incident ] | ENUM lang | | STRING formatid | +-----------------+

                  Figure 1: IODEF-Document Class

The aggregate class that constitute IODEF-Document is:

Incident

  One or more.  The information related to a single incident.

The IODEF-Document class has three attributes:

version

  Required.  STRING.  The IODEF specification version number to
  which this IODEF document conforms.  The value of this attribute
  MUST be "1.00"

lang

  Required.  ENUM.  A valid language code per RFC 4646 [7]
  constrained by the definition of "xs:language".  The
  interpretation of this code is described in Section 6.

formatid

  Optional.  STRING.  A free-form string to convey processing
  instructions to the recipient of the document.  Its semantics must
  be negotiated out-of-band.

Incident Class

Every incident is represented by an instance of the Incident class. This class provides a standardized representation for commonly exchanged incident data.

+--------------------+ | Incident | +--------------------+ | ENUM purpose |<>----------[ IncidentID ] | STRING ext-purpose |<>--{0..1}--[ AlternativeID ] | ENUM lang |<>--{0..1}--[ RelatedActivity ] | ENUM restriction |<>--{0..1}--[ DetectTime ] | |<>--{0..1}--[ StartTime ] | |<>--{0..1}--[ EndTime ] | |<>----------[ ReportTime ] | |<>--{0..*}--[ Description ] | |<>--{1..*}--[ Assessment ] | |<>--{0..*}--[ Method ] | |<>--{1..*}--[ Contact ] | |<>--{0..*}--[ EventData ] | |<>--{0..1}--[ History ] | |<>--{0..*}--[ AdditionalData ] +--------------------+

                   Figure 2: The Incident Class

The aggregate classes that constitute Incident are:

IncidentID

  One. An incident tracking number assigned to this incident by the
  CSIRT that generated the IODEF document.

AlternativeID

  Zero or one.  The incident tracking numbers used by other CSIRTs
  to refer to the incident described in the document.

RelatedActivity

  Zero or one.  The incident tracking numbers of related incidents.

DetectTime

  Zero or one.  The time the incident was first detected.

StartTime

  Zero or one.  The time the incident started.

EndTime

  Zero or one.  The time the incident ended.

ReportTime

  One. The time the incident was reported.

Description

  Zero or more.  ML_STRING.  A free-form textual description of the
  incident.

Assessment

  One or more.  A characterization of the impact of the incident.

Method

  Zero or more.  The techniques used by the intruder in the
  incident.

Contact

  One or more.  Contact information for the parties involved in the
  incident.

EventData

  Zero or more.  Description of the events comprising the incident.

History

  Zero or one.  A log of significant events or actions that occurred
  during the course of handling the incident.

AdditionalData

  Zero or more.  Mechanism by which to extend the data model.

The Incident class has four attributes:

purpose

  Required.  ENUM.  The purpose attribute represents the reason why
  the IODEF document was created.  It is closely related to the
  Expectation class (Section 3.13).  This attribute is defined as an
  enumerated list:

  1.  traceback.  The document was sent for trace-back purposes.

  2.  mitigation.  The document was sent to request aid in
      mitigating the described activity.

  3.  reporting.  The document was sent to comply with reporting
      requirements.

  4.  other.  The document was sent for purposes specified in the
      Expectation class.

  5.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-purpose

  Optional.  STRING.  A means by which to extend the purpose
  attribute.  See Section 5.1.

lang

  Optional.  ENUM.  A valid language code per RFC 4646 [7]
  constrained by the definition of "xs:language".  The
  interpretation of this code is described in Section 6.

restriction

  Optional.  ENUM.  This attribute indicates the disclosure
  guidelines to which the sender expects the recipient to adhere for
  the information represented in this class and its children.  This
  guideline provides no security since there are no specified
  technical means to ensure that the recipient of the document
  handles the information as the sender requested.

  The value of this attribute is logically inherited by the children
  of this class.  That is to say, the disclosure rules applied to
  this class, also apply to its children.

  It is possible to set a granular disclosure policy, since all of
  the high-level classes (i.e., children of the Incident class) have
  a restriction attribute.  Therefore, a child can override the
  guidelines of a parent class, be it to restrict or relax the
  disclosure rules (e.g., a child has a weaker policy than an
  ancestor; or an ancestor has a weak policy, and the children
  selectively apply more rigid controls).  The implicit value of the
  restriction attribute for a class that did not specify one can be
  found in the closest ancestor that did specify a value.

  This attribute is defined as an enumerated value with a default
  value of "private".  Note that the default value of the
  restriction attribute is only defined in the context of the
  Incident class.  In other classes where this attribute is used, no
  default is specified.

  1.  public.  There are no restrictions placed in the information.

  2.  need-to-know.  The information may be shared with other
      parties that are involved in the incident as determined by the
      recipient of this document (e.g., multiple victim sites can be
      informed of each other).

  3.  private.  The information may not be shared.

  4.  default.  The information can be shared according to an
      information disclosure policy pre-arranged by the
      communicating parties.

IncidentID Class

The IncidentID class represents an incident tracking number that is unique in the context of the CSIRT and identifies the activity characterized in an IODEF Document. This identifier would serve as an index into the CSIRT incident handling system. The combination of the name attribute and the string in the element content MUST be a globally unique identifier describing the activity. Documents generated by a given CSIRT MUST NOT reuse the same value unless they are referencing the same incident.

                  Figure 3: The IncidentID Class

The IncidentID class has three attributes:

name

  Required.  STRING.  An identifier describing the CSIRT that
  created the document.  In order to have a globally unique CSIRT
  name, the fully qualified domain name associated with the CSIRT
  MUST be used.

instance

  Optional.  STRING.  An identifier referencing a subset of the
  named incident.

restriction

  Optional.  ENUM.  This attribute has been defined in Section 3.2.

AlternativeID Class

The AlternativeID class lists the incident tracking numbers used by CSIRTs, other than the one generating the document, to refer to the identical activity described the IODEF document. A tracking number listed as an AlternativeID references the same incident detected by

another CSIRT. The incident tracking numbers of the CSIRT that generated the IODEF document should never be considered an AlternativeID.

     +------------------+
     | AlternativeID    |
     +------------------+
     | ENUM restriction |<>--{1..*}--[ IncidentID ]
     |                  |
     +------------------+

                 Figure 4: The AlternativeID Class

The aggregate class that constitutes AlternativeID is:

IncidentID

  One or more.  The incident tracking number of another CSIRT.

The AlternativeID class has one attribute:

restriction

  Optional.  ENUM.  This attribute has been defined in Section 3.2.

RelatedActivity Class

The RelatedActivity class lists either incident tracking numbers of incidents or URLs (not both) that refer to activity related to the one described in the IODEF document. These references may be to local incident tracking numbers or to those of other CSIRTs.

The specifics of how a CSIRT comes to believe that two incidents are related are considered out of scope.

     +------------------+
     | RelatedActivity  |
     +------------------+
     | ENUM restriction |<>--{0..*}--[ IncidentID ]
     |                  |<>--{0..*}--[ URL        ]
     +------------------+

                  Figure 5: RelatedActivity Class

The aggregate classes that constitutes RelatedActivity are:

IncidentID

  One or more.  The incident tracking number of a related incident.

URL

  One or more.  URL.  A URL to activity related to this incident.

The RelatedActivity class has one attribute:

restriction

  Optional.  ENUM.  This attribute has been defined in Section 3.2.

AdditionalData Class

The AdditionalData class serves as an extension mechanism for information not otherwise represented in the data model. For relatively simple information, atomic data types (e.g., integers, strings) are provided with a mechanism to annotate their meaning. The class can also be used to extend the data model (and the associated Schema) to support proprietary extensions by encapsulating entire XML documents conforming to another Schema (e.g., IDMEF). A detailed discussion for extending the data model and the schema can be found in Section 5.

Unlike XML, which is self-describing, atomic data must be documented to convey its meaning. This information is described in the 'meaning' attribute. Since these description are outside the scope of the specification, some additional coordination may be required to ensure that a recipient of a document using the AdditionalData classes can make sense of the custom extensions.

                Figure 6: The AdditionalData Class

The AdditionalData class has five attributes:

dtype

  Required.  ENUM.  The data type of the element content.  The
  permitted values for this attribute are shown below.  The default
  value is "string".

  1.   boolean.  The element content is of type BOOLEAN.

  2.   byte.  The element content is of type BYTE.

  3.   character.  The element content is of type CHARACTER.

  4.   date-time.  The element content is of type DATETIME.

  5.   integer.  The element content is of type INTEGER.

  6.   portlist.  The element content is of type PORTLIST.

  7.   real.  The element content is of type REAL.

  8.   string.  The element content is of type STRING.

  9.   file.  The element content is a base64 encoded binary file
       encoded as a BYTE[] type.

  10.  frame.  The element content is a layer-2 frame encoded as a
       HEXBIN type.

  11.  packet.  The element content is a layer-3 packet encoded as a
       HEXBIN type.

  12.  ipv4-packet.  The element content is an IPv4 packet encoded
       as a HEXBIN type.

  13.  ipv6-packet.  The element content is an IPv6 packet encoded
       as a HEXBIN type.

  14.  path.  The element content is a file-system path encoded as a
       STRING type.

  15.  url.  The element content is of type URL.

  16.  csv.  The element content is a common separated value (CSV)
       list per Section 2 of [20] encoded as a STRING type.

  17.  winreg.  The element content is a Windows registry key
       encoded as a STRING type.

  18.  xml.  The element content is XML (see Section 5).

  19.  ext-value.  An escape value used to extend this attribute.
       See Section 5.1.

ext-dtype

  Optional.  STRING.  A means by which to extend the dtype
  attribute.  See Section 5.1.

meaning

  Optional.  STRING.  A free-form description of the element
  content.

formatid

  Optional.  STRING.  An identifier referencing the format and
  semantics of the element content.

restriction

  Optional.  ENUM.  This attribute has been defined in Section 3.2.

Contact Class

The Contact class describes contact information for organizations and personnel involved in the incident. This class allows for the naming of the involved party, specifying contact information for them, and identifying their role in the incident.

People and organizations are treated interchangeably as contacts; one can be associated with the other using the recursive definition of the class (the Contact class is aggregated into the Contact class). The 'type' attribute disambiguates the type of contact information being provided.

The inheriting definition of Contact provides a way to relate information without requiring the explicit use of identifiers in the classes or duplication of data. A complete point of contact is derived by a particular traversal from the root Contact class to the leaf Contact class. As such, multiple points of contact might be specified in a single instance of a Contact class. Each child Contact class logically inherits contact information from its ancestors.

+------------------+ | Contact | +------------------+ | ENUM role |<>--{0..1}--[ ContactName ] | STRING ext-role |<>--{0..*}--[ Description ] | ENUM type |<>--{0..*}--[ RegistryHandle ] | STRING ext-type |<>--{0..1}--[ PostalAddress ] | ENUM restriction |<>--{0..*}--[ Email ] | |<>--{0..*}--[ Telephone ] | |<>--{0..1}--[ Fax ] | |<>--{0..1}--[ Timezone ] | |<>--{0..*}--[ Contact ] | |<>--{0..*}--[ AdditionalData ] +------------------+

                    Figure 7: The Contact Class

The aggregate classes that constitute the Contact class are:

ContactName

  Zero or one.  ML_STRING.  The name of the contact.  The contact
  may either be an organization or a person.  The type attribute
  disambiguates the semantics.

Description

  Zero or many.  ML_STRING.  A free-form description of this
  contact.  In the case of a person, this is often the
  organizational title of the individual.

RegistryHandle

  Zero or many.  A handle name into the registry of the contact.

PostalAddress

  Zero or one.  The postal address of the contact.

Email

  Zero or many.  The email address of the contact.

Telephone

  Zero or many.  The telephone number of the contact.

Fax

  Zero or one.  The facsimile telephone number of the contact.

Timezone

  Zero or one.  TIMEZONE.  The timezone in which the contact resides
  formatted according to Section 2.9.

Contact

  Zero or many.  A Contact instance contained within another Contact
  instance inherits the values of the parent(s).  This recursive
  definition can be used to group common data pertaining to multiple
  points of contact and is especially useful when listing multiple
  contacts at the same organization.

AdditionalData

  Zero or many.  A mechanism by which to extend the data model.

At least one of the aggregate classes MUST be present in an instance of the Contact class. This is not enforced in the IODEF schema as there is no simple way to accomplish it.

The Contact class has five attributes:

role

  Required.  ENUM.  Indicates the role the contact fulfills.  This
  attribute is defined as an enumerated list:

  1.  creator.  The entity that generate the document.

  2.  admin.  An administrative contact for a host or network.

  3.  tech.  A technical contact for a host or network.

  4.  irt.  The CSIRT involved in handling the incident.

  5.  cc.  An entity that is to be kept informed about the handling
      of the incident.

  6.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-role

  Optional.  STRING.  A means by which to extend the role attribute.
  See Section 5.1.

type

  Required.  ENUM.  Indicates the type of contact being described.
  This attribute is defined as an enumerated list:

  1.  person.  The information for this contact references an
      individual.

  2.  organization.  The information for this contact references an
      organization.

  3.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-type

  Optional.  STRING.  A means by which to extend the type attribute.
  See Section 5.1.

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

RegistryHandle Class

The RegistryHandle class represents a handle into an Internet registry or community-specific database. The handle is specified in the element content and the type attribute specifies the database.

+---------------------+ | RegistryHandle | +---------------------+ | STRING | | | | ENUM registry | | STRING ext-registry | +---------------------+

                Figure 8: The RegistryHandle Class

The RegistryHandle class has two attributes:

registry

  Required.  ENUM.  The database to which the handle belongs.  The
  default value is 'local'.  The possible values are:

  1.  internic.  Internet Network Information Center

  2.  apnic.  Asia Pacific Network Information Center

  3.  arin.  American Registry for Internet Numbers

  4.  lacnic.  Latin-American and Caribbean IP Address Registry

  5.  ripe.  Reseaux IP Europeens

  6.  afrinic.  African Internet Numbers Registry

  7.  local.  A database local to the CSIRT

  8.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-registry

  Optional.  STRING.  A means by which to extend the registry
  attribute.  See Section 5.1.

PostalAddress Class

The PostalAddress class specifies a postal address formatted according to the POSTAL data type (Section 2.11).

+---------------------+ | PostalAddress | +---------------------+ | POSTAL | | | | ENUM meaning | | ENUM lang | +---------------------+

                 Figure 9: The PostalAddress Class

The PostalAddress class has two attributes:

meaning

  Optional.  ENUM.  A free-form description of the element content.

lang

  Required.  ENUM.  A valid language code per RFC 4646 [7]
  constrained by the definition of "xs:language".  The
  interpretation of this code is described in Section 6.

Email Class

The Email class specifies an email address formatted according to EMAIL data type (Section 2.14).

+--------------+ | Email | +--------------+ | EMAIL | | | | ENUM meaning | +--------------+

                    Figure 10: The Email Class

The Email class has one attribute:

meaning

  Optional.  ENUM.  A free-form description of the element content.

Telephone and Fax Classes

The Telephone and Fax classes specify a voice or fax telephone number respectively, and are formatted according to PHONE data type (Section 2.13).

+--------------------+ | {Telephone | Fax } | +--------------------+ | PHONE | | | | ENUM meaning | +--------------------+

             Figure 11: The Telephone and Fax Classes

The Telephone class has one attribute:

meaning

  Optional.  ENUM.  A free-form description of the element content
  (e.g., hours of coverage for a given number).

Time Classes

The data model uses five different classes to represent a timestamp. Their definition is identical, but each has a distinct name to convey a difference in semantics.

The element content of each class is a timestamp formatted according to the DATETIME data type (see Section 2.8).

+----------------------------------+ | {Start| End| Report| Detect}Time | +----------------------------------+ | DATETIME | +----------------------------------+

                    Figure 12: The Time Classes

StartTime

The StartTime class represents the time the incident began.

EndTime

The EndTime class represents the time the incident ended.

DetectTime

The DetectTime class represents the time the first activity of the incident was detected.

ReportTime

The ReportTime class represents the time the incident was reported. This timestamp SHOULD coincide to the time at which the IODEF document is generated.

DateTime

The DateTime class is a generic representation of a timestamp. Its semantics should be inferred from the parent class in which it is aggregated.

Method Class

The Method class describes the methodology used by the intruder to perpetrate the events of the incident. This class consists of a list of references describing the attack method and a free form description of the technique.

+------------------+ | Method | +------------------+ | ENUM restriction |<>--{0..*}--[ Reference ] | |<>--{0..*}--[ Description ] | |<>--{0..*}--[ AdditionalData ] +------------------+

                    Figure 13: The Method Class

The Method class is composed of three aggregate classes.

Reference

  Zero or many.  A reference to a vulnerability, malware sample,
  advisory, or analysis of an attack technique.

Description

  Zero or many.  ML_STRING.  A free-form text description of the
  methodology used by the intruder.

AdditionalData

  Zero or many.  A mechanism by which to extend the data model.

Either an instance of the Reference or Description class MUST be present.

The Method class has one attribute:

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

Reference Class

The Reference class is a reference to a vulnerability, IDS alert, malware sample, advisory, or attack technique. A reference consists of a name, a URL to this reference, and an optional description.

+------------------+ | Reference | +------------------+ | |<>----------[ ReferenceName ] | |<>--{0..*}--[ URL ] | |<>--{0..*}--[ Description ] +------------------+

                  Figure 14: The Reference Class

The aggregate classes that constitute Reference:

ReferenceName

  One. ML_STRING.  Name of the reference.

URL

  Zero or many.  URL.  A URL associated with the reference.

Description

  Zero or many.  ML_STRING.  A free-form text description of this
  reference.

3.10. Assessment Class

The Assessment class describes the technical and non-technical repercussions of the incident on the CSIRT's constituency.

This class was derived from the IDMEF[17].

+------------------+
| Assessment       |
+------------------+
| ENUM occurrence  |<>--{0..*}--[ Impact         ]
| ENUM restriction |<>--{0..*}--[ TimeImpact     ]
|                  |<>--{0..*}--[ MonetaryImpact ]
|                  |<>--{0..*}--[ Counter        ]
|                  |<>--{0..1}--[ Confidence     ]
|                  |<>--{0..*}--[ AdditionalData ]
+------------------+

                    Figure 15: Assessment Class

The aggregate classes that constitute Assessment are:

Impact

  Zero or many.  Technical impact of the incident on a network.

TimeImpact

  Zero or many.  Impact of the activity measured with respect to
  time.

MonetaryImpact

  Zero or many.  Impact of the activity measured with respect to
  financial loss.

Counter

  Zero or more.  A counter with which to summarize the magnitude of
  the activity.

Confidence

  Zero or one.  An estimate of confidence in the assessment.

AdditionalData

  Zero or many.  A mechanism by which to extend the data model.

A least one instance of the possible three impact classes (i.e., Impact, TimeImpact, or MonetaryImpact) MUST be present.

The Assessment class has two attributes:

occurrence

  Optional.  ENUM.  Specifies whether the assessment is describing
  actual or potential outcomes.  The default is "actual" and is
  assumed if not specified.

  1.  actual.  This assessment describes activity that has occurred.

  2.  potential.  This assessment describes potential activity that
      might occur.

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

3.10.1. Impact Class

The Impact class allows for categorizing and describing the technical impact of the incident on the network of an organization.

This class is based on the IDMEF [17].

                      Figure 16: Impact Class

The element content will be a free-form textual description of the impact.

The Impact class has five attributes:

lang

  Required.  ENUM.  A valid language code per RFC 4646 [7]
  constrained by the definition of "xs:language".  The
  interpretation of this code is described in Section 6.

severity

  Optional.  ENUM.  An estimate of the relative severity of the
  activity.  The permitted values are shown below.  There is no
  default value.

  1.  low.  Low severity

  2.  medium.  Medium severity

  3.  high.  High severity

completion

  Optional.  ENUM.  An indication whether the described activity was
  successful.  The permitted values are shown below.  There is no
  default value.

  1.  failed.  The attempted activity was not successful.

  2.  succeeded.  The attempted activity succeeded.

type

  Required.  ENUM.  Classifies the malicious activity into incident
  categories.  The permitted values are shown below.  The default
  value is "other".

  1.   admin.  Administrative privileges were attempted.

  2.   dos.  A denial of service was attempted.

  3.   file.  An action that impacts the integrity of a file or
       database was attempted.

  4.   info-leak.  An attempt was made to exfiltrate information.

  5.   misconfiguration.  An attempt was made to exploit a mis-
       configuration in a system.

  6.   policy.  Activity violating site's policy was attempted.

  7.   recon.  Reconnaissance activity was attempted.

  8.   social-engineering.  A social engineering attack was
       attempted.

  9.   user.  User privileges were attempted.

  10.  unknown.  The classification of this activity is unknown.

  11.  ext-value.  An escape value used to extend this attribute.
       See Section 5.1.

ext-type

  Optional.  STRING.  A means by which to extend the type attribute.
  See Section 5.1.

3.10.2. TimeImpact Class

The TimeImpact class describes the impact of the incident on an organization as a function of time. It provides a way to convey down time and recovery time.

     +---------------------+
     | TimeImpact          |
     +---------------------+
     | REAL                |
     |                     |
     | ENUM severity       |
     | ENUM metric         |
     | STRING ext-metric   |
     | ENUM duration       |
     | STRING ext-duration |
     +---------------------+

                    Figure 17: TimeImpact Class

The element content is a positive, floating point (REAL) number specifying a unit of time. The duration and metric attributes will imply the semantics of the element content.

The TimeImpact class has five attributes:

severity

  Optional.  ENUM.  An estimate of the relative severity of the
  activity.  The permitted values are shown below.  There is no
  default value.

  1.  low.  Low severity

  2.  medium.  Medium severity

  3.  high.  High severity

metric

  Required.  ENUM.  Defines the metric in which the time is
  expressed.  The permitted values are shown below.  There is no
  default value.

  1.  labor.  Total staff-time to recovery from the activity (e.g.,
      2 employees working 4 hours each would be 8 hours).

  2.  elapsed.  Elapsed time from the beginning of the recovery to
      its completion (i.e., wall-clock time).

  3.  downtime.  Duration of time for which some provided service(s)
      was not available.

  4.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-metric

  Optional.  STRING.  A means by which to extend the metric
  attribute.  See Section 5.1.

duration

  Required.  ENUM.  Defines a unit of time, that when combined with
  the metric attribute, fully describes a metric of impact that will
  be conveyed in the element content.  The permitted values are
  shown below.  The default value is "hour".

  1.  second.  The unit of the element content is seconds.

  2.  minute.  The unit of the element content is minutes.

  3.  hour.  The unit of the element content is hours.

  4.  day.  The unit of the element content is days.

  5.  month.  The unit of the element content is months.

  6.  quarter.  The unit of the element content is quarters.

  7.  year.  The unit of the element content is years.

  8.  ext-value.  An escape value used to extend this attribute.
      See Section 5.1.

ext-duration

  Optional.  STRING.  A means by which to extend the duration
  attribute.  See Section 5.1.

3.10.3. MonetaryImpact Class

The MonetaryImpact class describes the financial impact of the activity on an organization. For example, this impact may consider losses due to the cost of the investigation or recovery, diminished

productivity of the staff, or a tarnished reputation that will affect future opportunities.

     +------------------+
     | MonetaryImpact   |
     +------------------+
     | REAL             |
     |                  |
     | ENUM severity    |
     | STRING currency  |
     +------------------+

                  Figure 18: MonetaryImpact Class

The element content is a positive, floating point number (REAL) specifying a unit of currency described in the currency attribute.

The MonetaryImpact class has two attributes:

severity

  Optional.  ENUM.  An estimate of the relative severity of the
  activity.  The permitted values are shown below.  There is no
  default value.

  1.  low.  Low severity

  2.  medium.  Medium severity

  3.  high.  High severity

currency

  Required.  STRING.  Defines the currency in which the monetary
  impact is expressed.  The permitted values are defined in ISO
  4217:2001, Codes for the representation of currencies and funds
  [14].  There is no default value.

3.10.4. Confidence Class

The Confidence class represents a best estimate of the validity and accuracy of the described impact (see Section 3.10) of the incident activity. This estimate can be expressed as a category or a numeric calculation.

This class if based upon the IDMEF [17]).

     +------------------+
     | Confidence       |
     +------------------+
     | REAL             |
     |                  |
     | ENUM rating      |
     +------------------+

                    Figure 19: Confidence Class

The element content expresses a numerical assessment in the confidence of the data when the value of the rating attribute is "numeric". Otherwise, this element should be empty.

The Confidence class has one attribute.

rating

  Required.  ENUM.  A rating of the analytical validity of the
  specified Assessment.  The permitted values are shown below.
  There is no default value.

  1.  low.  Low confidence in the validity.

  2.  medium.  Medium confidence in the validity.

  3.  high.  High confidence in the validity.

  4.  numeric.  The element content contains a number that conveys
      the confidence of the data.  The semantics of this number
      outside the scope of this specification.

3.11. History Class

The History class is a log of the significant events or actions performed by the involved parties during the course of handling the incident.

The level of detail maintained in this log is left up to the discretion of those handling the incident.

+------------------+ | History | +------------------+ | ENUM restriction |<>--{1..*}--[ HistoryItem ] | | +------------------+

                   Figure 20: The History Class

The class that constitutes History is:

HistoryItem

  One or many.  Entry in the history log of significant events or
  actions performed by the involved parties.

The History class has one attribute:

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

3.11.1. HistoryItem Class

The HistoryItem class is an entry in the History (Section 3.11) log that documents a particular action or event that occurred in the course of handling the incident. The details of the entry are a free-form description, but each can be categorized with the type attribute.

+-------------------+ | HistoryItem | +-------------------+ | ENUM restriction |<>----------[ DateTime ] | ENUM action |<>--{0..1}--[ IncidentId ] | STRING ext-action |<>--{0..1}--[ Contact ] | |<>--{0..*}--[ Description ] | |<>--{0..*}--[ AdditionalData ] +-------------------+

                   Figure 21: HistoryItem Class

The aggregate classes that constitute HistoryItem are:

DateTime

  One. Timestamp of this entry in the history log (e.g., when the
  action described in the Description was taken).

IncidentID

  Zero or One. In a history log created by multiple parties, the
  IncidentID provides a mechanism to specify which CSIRT created a
  particular entry and references this organization's incident
  tracking number.  When a single organization is maintaining the
  log, this class can be ignored.

Contact

  Zero or One. Provides contact information for the person that
  performed the action documented in this class.

Description

  Zero or many.  ML_STRING.  A free-form textual description of the
  action or event.

AdditionalData

  Zero or many.  A mechanism by which to extend the data model.

The HistoryItem class has three attributes:

restriction

  Optional.  ENUM.  This attribute has been defined in Section 3.2.

action

  Required.  ENUM.  Classifies a performed action or occurrence
  documented in this history log entry.  As activity will likely
  have been instigated either through a previously conveyed
  expectation or internal investigation, this attribute is identical
  to the category attribute of the Expectation class.  The
  difference is only one of tense.  When an action is in this class,
  it has been completed.  See Section 3.13.

ext-action

  Optional.  STRING.  A means by which to extend the action
  attribute.  See Section 5.1.

3.12. EventData Class

The EventData class describes a particular event of the incident for a given set of hosts or networks. This description includes the systems from which the activity originated and those targeted, an assessment of the techniques used by the intruder, the impact of the activity on the organization, and any forensic evidence discovered.

+------------------+ | EventData | +------------------+ | ENUM restriction |<>--{0..*}--[ Description ] | |<>--{0..1}--[ DetectTime ] | |<>--{0..1}--[ StartTime ] | |<>--{0..1}--[ EndTime ] | |<>--{0..*}--[ Contact ] | |<>--{0..1}--[ Assessment ] | |<>--{0..*}--[ Method ] | |<>--{0..*}--[ Flow ] | |<>--{0..*}--[ Expectation ] | |<>--{0..1}--[ Record ] | |<>--{0..*}--[ EventData ] | |<>--{0..*}--[ AdditionalData ] +------------------+

                  Figure 22: The EventData Class

The aggregate classes that constitute EventData are:

Description

  Zero or more.  ML_STRING.  A free-form textual description of the
  event.

DetectTime

  Zero or one.  The time the event was detected.

StartTime

  Zero or one.  The time the event started.

EndTime

  Zero or one.  The time the event ended.

Contact

  Zero or more.  Contact information for the parties involved in the
  event.

Assessment

  Zero or one.  The impact of the event on the target and the
  actions taken.

Method

  Zero or more.  The technique used by the intruder in the event.

Flow

  Zero or more.  A description of the systems or networks involved.

Expectation

  Zero or more.  The expected action to be performed by the
  recipient for the described event.

Record

  Zero or one.  Supportive data (e.g., log files) that provides
  additional information about the event.

EventData

  Zero or more.  EventData instances contained within another
  EventData instance inherit the values of the parent(s); this
  recursive definition can be used to group common data pertaining
  to multiple events.  When EventData elements are defined
  recursively, only the leaf instances (those EventData instances
  not containing other EventData instances) represent actual events.

AdditionalData

  Zero or more.  An extension mechanism for data not explicitly
  represented in the data model.

At least one of the aggregate classes MUST be present in an instance of the EventData class. This is not enforced in the IODEF schema as there is no simple way to accomplish it.

The EventData class has one attribute:

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

3.12.1. Relating the Incident and EventData Classes

There is substantial overlap in the Incident and EventData classes. Nevertheless, the semantics of these classes are quite different. The Incident class provides summary information about the entire incident, while the EventData class provides information about the individual events comprising the incident. In the most common case, the EventData class will provide more specific information for the general description provided in the Incident class. However, it may also be possible that the overall summarized information about the incident conflicts with some individual information in an EventData class when there is a substantial composition of various events in the incident. In such a case, the interpretation of the more specific EventData MUST supersede the more generic information provided in IncidentData.

3.12.2. Cardinality of EventData

The EventData class can be thought of as a container for the properties of an event in an incident. These properties include: the hosts involved, impact of the incident activity on the hosts, forensic logs, etc. With an instance of the EventData class, hosts (i.e., System class) are grouped around these common properties.

The recursive definition (or instance property inheritance) of the EventData class (the EventData class is aggregated into the EventData class) provides a way to related information without requiring the explicit use of unique attribute identifiers in the classes or duplicating information. Instead, the relative depth (nesting) of a class is used to group (relate) information.

For example, an EventData class might be used to describe two machines involved in an incident. This description can be achieved using multiple instances of the Flow class. It happens that there is a common technical contact (i.e., Contact class) for these two machines, but the impact (i.e., Assessment class) on them is different. A depiction of the representation for this situation can be found in Figure 23.

            Figure 23: Recursion in the EventData Class

3.13. Expectation Class

The Expectation class conveys to the recipient of the IODEF document the actions the sender is requesting. The scope of the requested action is limited to purview of the EventData class in which this class is aggregated.

+-------------------+ | Expectation | +-------------------+ | ENUM restriction |<>--{0..*}--[ Description ] | ENUM severity |<>--{0..1}--[ StartTime ] | ENUM action |<>--{0..1}--[ EndTime ] | STRING ext-action |<>--{0..1}--[ Contact ] +-------------------+

                 Figure 24: The Expectation Class

The aggregate classes that constitute Expectation are:

Description

  Zero or many.  ML_STRING.  A free-form description of the desired
  action(s).

StartTime

  Zero or one.  The time at which the action should be performed.  A
  timestamp that is earlier than the ReportTime specified in the
  Incident class denotes that the expectation should be fulfilled as
  soon as possible.  The absence of this element leaves the
  execution of the expectation to the discretion of the recipient.

EndTime

  Zero or one.  The time by which the action should be completed.
  If the action is not carried out by this time, it should no longer
  be performed.

Contact

  Zero or one.  The expected actor for the action.

The Expectations class has four attributes:

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

severity

  Optional.  ENUM.  Indicates the desired priority of the action.
  This attribute is an enumerated list with no default value, and
  the semantics of these relative measures are context dependent.

  1.  low.  Low priority

  2.  medium.  Medium priority

  3.  high.  High priority

action

  Optional.  ENUM.  Classifies the type of action requested.  This
  attribute is an enumerated list with no default value.

  1.   nothing.  No action is requested.  Do nothing with the
       information.

  2.   contact-source-site.  Contact the site(s) identified as the
       source of the activity.

  3.   contact-target-site.  Contact the site(s) identified as the
       target of the activity.

  4.   contact-sender.  Contact the originator of the document.

  5.   investigate.  Investigate the systems(s) listed in the event.

  6.   block-host.  Block traffic from the machine(s) listed as
       sources the event.

  7.   block-network.  Block traffic from the network(s) lists as
       sources in the event.

  8.   block-port.  Block the port listed as sources in the event.

  9.   rate-limit-host.  Rate-limit the traffic from the machine(s)
       listed as sources in the event.

  10.  rate-limit-network.  Rate-limit the traffic from the
       network(s) lists as sources in the event.

  11.  rate-limit-port.  Rate-limit the port(s) listed as sources in
       the event.

  12.  remediate-other.  Remediate the activity in a way other than
       by rate limiting or blocking.

  13.  status-triage.  Conveys receipts and the triaging of an
       incident.

  14.  status-new-info.  Conveys that new information was received
       for this incident.

  15.  other.  Perform some custom action described in the
       Description class.

  16.  ext-value.  An escape value used to extend this attribute.
       See Section 5.1.

ext-action

  Optional.  STRING.  A means by which to extend the action
  attribute.  See Section 5.1.

3.14. Flow Class

The Flow class groups related the source and target hosts.

+------------------+ | Flow | +------------------+ | |<>--{1..*}--[ System ] +------------------+

                     Figure 25: The Flow Class

The aggregate class that constitutes Flow is:

System

  One or More.  A host or network involved in an event.

The Flow System class has no attributes.

3.15. System Class

The System class describes a system or network involved in an event. The systems or networks represented by this class are categorized according to the role they played in the incident through the category attribute. The value of this category attribute dictates the semantics of the aggregated classes in the System class. If the category attribute has a value of "source", then the aggregated classes denote the machine and service from which the activity is originating. With a category attribute value of "target" or "intermediary", then the machine or service is the one targeted in the activity. A value of "sensor" dictates that this System was part of an instrumentation to monitor the network.

+---------------------+ | System | +---------------------+ | ENUM restriction |<>----------[ Node ] | ENUM category |<>--{0..*}--[ Service ] | STRING ext-category |<>--{0..*}--[ OperatingSystem ] | STRING interface |<>--{0..*}--[ Counter ] | ENUM spoofed |<>--{0..*}--[ Description ] | |<>--{0..*}--[ AdditionalData ] +---------------------+

                    Figure 26: The System Class

The aggregate classes that constitute System are:

Node

  One. A host or network involved in the incident.

Service

  Zero or more.  A network service running on the system.

OperatingSystem

  Zero or one.  The operating system running on the system.

Counter

  Zero or more.  A counter with which to summarize properties of
  this host or network.

Description

  Zero or more.  ML_STRING.  A free-form text description of the
  System.

AdditionalData

  Zero or many.  A mechanism by which to extend the data model.

The System class has five attributes:

restriction

  Optional.  ENUM.  This attribute is defined in Section 3.2.

Processing Considerations

This section defines additional requirements on creating and parsing IODEF documents.

Encoding

Every IODEF document MUST begin with an XML declaration, and MUST specify the XML version used. If UTF-8 encoding is not used, the character encoding MUST also be explicitly specified. The IODEF conforms to all XML data encoding conventions and constraints.

The XML declaration with no character encoding will read as follows:

<?xml version="1.0" ?>

When a character encoding is specified, the XML declaration will read like the following:

<?xml version="1.0" encoding="charset" ?>

Where "charset" is the name of the character encoding as registered with the Internet Assigned Numbers Authority (IANA), see [9].

The following characters have special meaning in XML and MUST be escaped with their entity reference equivalent: "&", "<", ">", "\"" (double quotation mark), and "'" (apostrophe). These entity references are "&", "<", ">", """, and "'" respectively.

IODEF Namespace

The IODEF schema declares a namespace of "urn:ietf:params:xml:ns:iodef-1.0" and registers it per [4]. Each IODEF document SHOULD include a valid reference to the IODEF schema using the "xsi:schemaLocation" attribute. An example of such a declaration would look as follows:

<IODEF-Document

  version="1.00" lang="en-US"
  xmlns:iodef="urn:ietf:params:xml:ns:iodef-1.0"
  xsi:schemaLocation="urn:ietf:params:xmls:schema:iodef-1.0">

Validation

The IODEF documents MUST be well-formed XML and SHOULD be validated against the schema described in Section 8. However, mere conformance to the schema is not sufficient for a semantically valid IODEF document. There is additional specification in the text of Section 3 that cannot be readily encoded in the schema and it must also be considered by an IODEF parser. The following is a list of discrepancies in what is more strictly specified in the normative text (Section 3), but not enforced in the IODEF schema:

o The elements or attributes that are defined as POSTAL, NAME,

  PHONE, and EMAIL data-types are implemented as "xs:string", but
  more rigid formatting requirements are specified in the text.

o The IODEF-Document@lang and MLStringType@lang attributes are

  declared as an "xs:language" that constrains values with a regular
  expression.  However, the value of this attribute still needs to
  be validated against the list of possible enumerated values is
  defined in [7].

o The MonetaryImpact@currency attribute is declared as an "xs:

  string", but the list of valid values as defined in [14].

o All of the aggregated classes Contact and EventData are optional

  in the schema, but at least one of these aggregated classes MUST
  be present.

o There are multiple conventions that can be used to categorize a

  system using the NodeRole class or to specify software with the
  Application and OperatingSystem classes.  IODEF parsers MUST
  accept incident reports that do not use these fields in accordance
  with local conventions.

o The Confidence@rating attribute determines whether the element

  content of Confidence should be empty.

o The Address@type attribute determines the format of the element

  content.

o The attributes AdditionalData@dtype and RecordItem@dtype derived

  from iodef:ExtensionType determine the semantics and formatting of
  the element content.

o Symmetry in the enumerated ports of a Portlist class is required

  between sources and targets.  See Section 3.17.

Extending the IODEF

In order to support the changing activity of CSIRTS, the IODEF data model will need to evolve along with them. This section discusses how new data elements that have no current representation in the data model can be incorporated into the IODEF. These techniques are designed so that adding new data will not require a change to the IODEF schema. With proven value, well documented extensions can be incorporated into future versions of the specification. However, this approach also supports private extensions relevant only to a closed consortium.

Extending the Enumerated Values of Attributes

The data model supports a means by which to add new enumerated values to an attribute. For each attribute that supports this extension technique, there is a corresponding attribute in the same element whose name is identical, less a prefix of "ext-". This special attribute is referred to as the extension attribute, and the attribute being extended is referred to as an extensible attribute. For example, an extensible attribute named "foo" will have a corresponding extension attribute named "ext-foo". An element may have many extensible, and therefore many extension, attributes.

In addition to a corresponding extension attribute, each extensible attribute has "ext-value" as one its possible values. This particular value serves as an escape sequence and has no valid meaning.

In order to add a new enumerated value to an extensible attribute, the value of this attribute MUST be set to "ext-value", and the new desired value MUST be set in the corresponding extension attribute. For example, an extended instance of the type attribute of the Impact class would look as follows:

<Impact type="ext-value" ext-type="new-attack-type">

A given extension attribute MUST NOT be set unless the corresponding extensible attribute has been set to "ext-value".

Extending Classes

The classes of the data model can be extended only through the use of the AdditionalData and RecordItem classes. These container classes, collectively referred to as the extensible classes, are implemented with the iodef:ExtensionType data type in the schema. They provide the ability to have new atomic or XML-encoded data elements in all of the top-level classes of the Incident class and a few of the more complicated subordinate classes. As there are multiple instances of the extensible classes in the data model, there is discretion on where to add a new data element. It is RECOMMENDED that the extension be placed in the most closely related class to the new information.

Extensions using the atomic data types (i.e., all values of the dtype attributes other than "xml") MUST:

1. Set the element content of extensible class to the desired value,

and

2. Set the dtype attribute to correspond to the data type of the

   element content.

The following guidelines exist for extensions using XML:

1. The element content of the extensible class MUST be set to the

   desired value and the dtype attribute MUST be set to "xml".

2. The extension schema MUST declare a separate namespace. It is

   RECOMMENDED that these extensions have the prefix "iodef-".

3. It is RECOMMENDED that extension schemas follow the naming

   convention of the IODEF data model.  The names of all elements
   are capitalized.  For composed names, a capital letter is used
   for each word.  Attribute names are lower case.

4. When a parser encounters an IODEF document with an extension it

   does not understand, this extension MUST be ignored (and not
   processed), but the remainder of the document MUST be processed.
   Parsers will be able to identify these extensions for which they
   have no processing logic through the namespace declaration.
   Parsers that encounter an unrecognized element in a namespace
   that they do support SHOULD reject the document as a syntax
   error.

5. Implementations SHOULD NOT download schemas at runtime due to the

   security implications, and extensions MUST NOT be required to
   provide a resolvable location of their schema.

The following schema and XML document excerpt provide a template for an extension schema and its use in the IODEF document.

This example schema defines a namespace of "iodef-extension1" and a single element named "newdata".

 <xs:schema
    targetNamespace="iodef-extension1.xsd"
    xmlns:iodef-extension1="iodef-extension1.xsd"
    xmlns:xs="http://www.w3.org/2001/XMLSchema">
    attributeFormDefault="unqualified"
    elementFormDefault="qualified">
  <xs:import
       namespace="urn:ietf:params:xml:ns:iodef-1.0"
       schemaLocation=" urn:ietf:params:xml:schema:iodef-1.0"/>

    <xs:element name="newdata" type="xs:string" />
 </xs:schema>

The following XML excerpt demonstrates the use of the above schema as an extension to the IODEF.

  <IODEF-Document
       version="1.00" lang="en-US"
       xmlns="urn:ietf:params:xml:ns:iodef-1.0"
       xmlns:iodef=" urn:ietf:params:xml:ns:iodef-1.0"
       xmlns:iodef-extension1="iodef-extension1.xsd"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="iodef-extension1.xsd">
      <Incident purpose="reporting">
      ...
      <AdditionalData dtype="xml" meaning="xml">
        <iodef-extension1:newdata>
           Field that could not be represented elsewhere
        </iodef-extension1:newdata>
      </AdditionalData>
      </Incident>
  </IODEF-Document>

Internationalization Issues

Internationalization and localization is of specific concern to the IODEF, since it is only through collaboration, often across language barriers, that certain incidents be resolved. The IODEF supports this goal by depending on XML constructs, and through explicit design choices in the data model.

Since IODEF is implemented as an XML Schema, it implicitly supports all the different character encodings, such as UTF-8 and UTF-16, possible with XML. Additionally, each IODEF document MUST specify the language in which their contents are encoded. The language can be specified with the attribute "xml:lang" (per Section 2.12 of [1]) in the top-level element (i.e., IODEF-Document@lang) and letting all other elements inherit that definition. All IODEF classes with a free-form text definition (i.e., all those defined of type iodef: MLStringType) can also specify a language different from the rest of the document. The valid language codes for the "xml:lang" attribute are described in RFC 4646 [7].

The data model supports multiple translations of free-form text. In the places where free-text is used for descriptive purposes, the given class always has a one-to-many cardinality to its parent (e.g., Description class). The intent is to allow the identical text to be encoded in different instances of the same class, but each being in a different language. This approach allows an IODEF document author to send recipients speaking different languages an identical document. The IODEF parser SHOULD extract the appropriate language relevant to the recipient.

While the intent of the data model is to provide internationalization and localization, the intent is not to do so at the detriment of interoperability. While the IODEF does support different languages, the data model also relies heavily on standardized enumerated attributes that can crudely approximate the contents of the document. With this approach, a CSIRT should be able to make some sense of an IODEF document it receives even if the text based data elements are written in a language unfamiliar to the analyst.

Examples

This section provides examples of an incident encoded in the IODEF. These examples do not necessarily represent the only way to encode a particular incident.

Worm

An example of a CSIRT reporting an instance of the Code Red worm.

<?xml version="1.0" encoding="UTF-8"?> <IODEF-Document version="1.00" lang="en"

 xmlns="urn:ietf:params:xml:ns:iodef-1.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="urn:ietf:params:xml:schema:iodef-1.0">
 <Incident purpose="reporting">
<IncidentID name="csirt.example.com">189493</IncidentID>
<ReportTime>2001-09-13T23:19:24+00:00</ReportTime>
<Description>Host sending out Code Red probes</Description>
<Assessment>
  <Impact completion="failed" type="admin"/>
</Assessment>
<Contact role="creator" type="organization">
  <ContactName>Example.com CSIRT</ContactName>
  <RegistryHandle registry="arin">example-com</RegistryHandle>
  <Email>[email protected]</Email>
</Contact>
<EventData>
  <Flow>
    <System category="source">
      <Node>
        <Address category="ipv4-addr">192.0.2.200</Address>
        <Counter type="event">57</Counter>
      </Node>
    </System>
    <System category="target">

      <Node>
        <Address category="ipv4-net">192.0.2.16/28</Address>
      </Node>
      <Service ip_protocol="6">
        <Port>80</Port>
      </Service>
    </System>
  </Flow>
  <Expectation action="block-host" />
  <Record>
    <RecordData>
      <DateTime>2001-09-13T18:11:21+02:00</DateTime>
      <Description>Web-server logs</Description>
      <RecordItem dtype="string">
      192.0.2.1 - - [13/Sep/2001:18:11:21 +0200] "GET /default.ida?
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      </RecordItem>
      <RecordItem dtype="url">
         http://mylogs.example.com/logs/httpd_access</RecordItem>
    </RecordData>
  </Record>
</EventData>
<History>
  <HistoryItem action="contact-source-site">
    <DateTime>2001-09-14T08:19:01+00:00</DateTime>
    <Description>Notification sent to
                 [email protected]</Description>
  </HistoryItem>
</History>
 </Incident>

</IODEF-Document>

Reconnaissance

An example of a CSIRT reporting a scanning activity.

<?xml version="1.0" encoding="UTF-8" ?>

<IODEF-Document version="1.00" lang="en"

 xmlns="urn:ietf:params:xml:ns:iodef-1.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="urn:ietf:params:xml:schema:iodef-1.0">
 <Incident purpose="reporting">
   <IncidentID name="csirt.example.com">59334</IncidentID>
   <ReportTime>2006-08-02T05:54:02-05:00</ReportTime>
   <Assessment>
     <Impact type="recon" completion="succeeded" />
   </Assessment>
   <Method>
     <Reference>
       <ReferenceName>nmap</ReferenceName>
       <URL>http://nmap.toolsite.example.com</URL>
     </Reference>
   </Method>
   <Contact role="creator" type="organization">
     <ContactName>CSIRT for example.com</ContactName>
     <Email>[email protected]</Email>
     <Telephone>+1 412 555 12345</Telephone>
     <Contact role="tech" type="person" restriction="need-to-know">
       <ContactName>Joe Smith</ContactName>
       <Email>[email protected]</Email>
     </Contact>
   </Contact>
   <EventData>
     <Flow>
       <System category="source">
         <Node>
           <Address category="ipv4-addr">192.0.2.200</Address>
         </Node>
         <Service ip_protocol="6">
           <Portlist>60524,60526,60527,60531</Portlist>
         </Service>
       </System>
       <System category="target">
         <Node>

           <Address category="ipv4-addr">192.0.2.201</Address>
         </Node>
         <Service ip_protocol="6">
           <Portlist>137-139,445</Portlist>
         </Service>
       </System>
     </Flow>
     <Flow>
       <System category="source">
         <Node>
           <Address category="ipv4-addr">192.0.2.240</Address>
         </Node>
       </System>
       <System category="target">
         <Node>
           <Address category="ipv4-net">192.0.2.64/28</Address>
         </Node>
         <Service ip_protocol="6">
           <Port>445</Port>
         </Service>
       </System>
     </Flow>
   </EventData>
 </Incident>

</IODEF-Document>

Bot-Net Reporting

An example of a CSIRT reporting a bot-network.

<?xml version="1.0" encoding="UTF-8" ?>
<IODEF-Document version="1.00" lang="en"

xmlns="urn:ietf:params:xml:ns:iodef-1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:ietf:params:xml:schema:iodef-1.0"> <Incident purpose="mitigation">

 <IncidentID name="csirt.example.com">908711</IncidentID>
 <ReportTime>2006-06-08T05:44:53-05:00</ReportTime>
 <Description>Large bot-net</Description>
 <Assessment>
   <Impact type="dos" severity="high" completion="succeeded" />

 </Assessment>
 <Method>
   <Reference>
     <ReferenceName>GT Bot</ReferenceName>
   </Reference>
   <Reference>
     <ReferenceName>CA-2003-22</ReferenceName>
     <URL>http://www.cert.org/advisories/CA-2003-22.html</URL>
     <Description>Root compromise via this IE vulnerability to
                  install the GT Bot</Description>
   </Reference>
 </Method>
 <Contact type="person" role="irt">
   <ContactName>Joe Smith</ContactName>
   <Email>[email protected]</Email>
 </Contact>
 <EventData>
   <Description>These hosts are compromised and acting as bots
                communicating with irc.example.com.</Description>
   <Flow>
     <System category="source">
       <Node>
         <Address category="ipv4-addr">192.0.2.1</Address>
       </Node>
       <Counter type="byte" duration="second">10000</Counter>
       <Description>bot</Description>
     </System>
     <System category="source">
       <Node>
         <Address category="ipv4-addr">192.0.2.3</Address>
       </Node>
       <Counter type="byte" duration="second">250000</Counter>
       <Description>bot</Description>
     </System>
     <System category="intermediate">
       <Node>
         <NodeName>irc.example.com</NodeName>
         <Address category="ipv4-addr">192.0.2.20</Address>
         <DateTime>2006-06-08T01:01:03-05:00</DateTime>

       </Node>
       <Description>IRC server on #give-me-cmd channel</Description>
     </System>
   </Flow>
   <Expectation action="investigate">
     <Description>Confirm the source and take machines off-line and
                  remediate</Description>
   </Expectation>
 </EventData>

</Incident>

</IODEF-Document>

Watch List

An example of a CSIRT conveying a watch-list.

<?xml version="1.0" encoding="UTF-8" ?> <IODEF-Document version="1.00" lang="en" formatid="watch-list-043"

 xmlns="urn:ietf:params:xml:ns:iodef-1.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="urn:ietf:params:xml:schema:iodef-1.0">
 <Incident purpose="reporting" restriction="private">
<IncidentID name="csirt.example.com">908711</IncidentID>
<ReportTime>2006-08-01T00:00:00-05:00</ReportTime>
<Description>Watch-list of known bad IPs or networks</Description>
<Assessment>
  <Impact type="admin" completion="succeeded" />
  <Impact type="recon" completion="succeeded" />
</Assessment>
<Contact type="organization" role="creator">
  <ContactName>CSIRT for example.com</ContactName>
  <Email>[email protected]</Email>
</Contact>
<EventData>
  <Flow>
    <System category="source">
      <Node>
        <Address category="ipv4-addr">192.0.2.53</Address>
      </Node>

      <Description>Source of numerous attacks</Description>
    </System>
  </Flow>
  <Expectation action="contact-sender" />
</EventData>
<EventData>
  <Flow>
    <System category="source">
      <Node>
        <Address category="ipv4-net">192.0.2.16/28</Address>
      </Node>
      <Description>
        Source of heavy scanning over past 1-month
      </Description>
    </System>
  </Flow>
  <Flow>
    <System category="source">
      <Node>
        <Address category="ipv4-addr">192.0.2.241</Address>
      </Node>
      <Description>C2 IRC server</Description>
    </System>
  </Flow>
  <Expectation action="block-host" />
</EventData>
 </Incident>

</IODEF-Document>

The IODEF Schema

 <?xml version="1.0" encoding="UTF-8"?>
 <xs:schema targetNamespace="urn:ietf:params:xml:ns:iodef-1.0"
         xmlns="urn:ietf:params:xml:ns:iodef-1.0"
         xmlns:iodef="urn:ietf:params:xml:ns:iodef-1.0"
         xmlns:xs="http://www.w3.org/2001/XMLSchema"
         elementFormDefault="qualified"
         attributeFormDefault="unqualified">

<xs:annotation>
  <xs:documentation>
  Incident Object Description Exchange Format v1.00, see RFC 5070

  </xs:documentation>
</xs:annotation>

<xs:element name="IODEF-Document">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:Incident"
                  maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="version"
                  type="xs:string" fixed="1.00"/>
    <xs:attribute name="lang"
                  type="xs:language" use="required"/>
    <xs:attribute name="formatid"
                  type="xs:string"/>
  </xs:complexType>
</xs:element>
<xs:element name="Incident">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:IncidentID"/>
      <xs:element ref="iodef:AlternativeID"
                  minOccurs="0"/>
      <xs:element ref="iodef:RelatedActivity"
                  minOccurs="0"/>
      <xs:element ref="iodef:DetectTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:StartTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:EndTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:ReportTime"/>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Assessment"
                  maxOccurs="unbounded"/>
      <xs:element ref="iodef:Method"
                  minOccurs="0" maxOccurs="unbounded"/>

      <xs:element ref="iodef:Contact"
                  maxOccurs="unbounded"/>
      <xs:element ref="iodef:EventData"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:History"
                  minOccurs="0"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="purpose" use="required">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="traceback"/>
          <xs:enumeration value="mitigation"/>
          <xs:enumeration value="reporting"/>
          <xs:enumeration value="other"/>
          <xs:enumeration value="ext-value"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="ext-purpose"
                  type="xs:string" use="optional"/>
    <xs:attribute name="lang"
                  type="xs:language"/>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type" default="private"/>
  </xs:complexType>
</xs:element>
<xs:element name="IncidentID" type="iodef:IncidentIDType"/>
<xs:complexType name="IncidentIDType">
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute name="name"
                    type="xs:string" use="required"/>
      <xs:attribute name="instance"
                    type="xs:string" use="optional"/>
      <xs:attribute name="restriction"
                    type="iodef:restriction-type" default="public"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>

<xs:element name="AlternativeID">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:IncidentID"
                  maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="RelatedActivity">
  <xs:complexType>
    <xs:choice>
      <xs:element ref="iodef:IncidentID"
                  maxOccurs="unbounded"/>
      <xs:element ref="iodef:URL"
                  maxOccurs="unbounded"/>
    </xs:choice>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="AdditionalData" type="iodef:ExtensionType"/>
<xs:element name="Contact">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:ContactName"
                  minOccurs="0"/>

      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:RegistryHandle"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:PostalAddress"
                  minOccurs="0"/>
      <xs:element ref="iodef:Email"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Telephone"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Fax"
                  minOccurs="0"/>
      <xs:element ref="iodef:Timezone"
                  minOccurs="0"/>
      <xs:element ref="iodef:Contact"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="role" use="required">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="creator"/>
          <xs:enumeration value="admin"/>
          <xs:enumeration value="tech"/>
          <xs:enumeration value="irt"/>
          <xs:enumeration value="cc"/>
          <xs:enumeration value="ext-value"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="ext-role"
                  type="xs:string" use="optional"/>
    <xs:attribute name="type" use="required">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="person"/>
          <xs:enumeration value="organization"/>
          <xs:enumeration value="ext-value"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="ext-type"
                  type="xs:string" use="optional"/>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>

<xs:element name="ContactName"
            type="iodef:MLStringType"/>
<xs:element name="RegistryHandle">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="xs:string">
        <xs:attribute name="registry">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="internic"/>
              <xs:enumeration value="apnic"/>
              <xs:enumeration value="arin"/>
              <xs:enumeration value="lacnic"/>
              <xs:enumeration value="ripe"/>
              <xs:enumeration value="afrinic"/>
              <xs:enumeration value="local"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-registry"
                      type="xs:string" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>

<xs:element name="PostalAddress">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="iodef:MLStringType">
        <xs:attribute name="meaning"
                      type="xs:string" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="Email" type="iodef:ContactMeansType"/>
<xs:element name="Telephone" type="iodef:ContactMeansType"/>
<xs:element name="Fax" type="iodef:ContactMeansType"/>

<xs:complexType name="ContactMeansType">
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute name="meaning"
                    type="xs:string" use="optional"/>
    </xs:extension>
  </xs:simpleContent>

</xs:complexType>

<xs:element name="DateTime"
            type="xs:dateTime"/>
<xs:element name="ReportTime"
            type="xs:dateTime"/>
<xs:element name="DetectTime"
            type="xs:dateTime"/>
<xs:element name="StartTime"
            type="xs:dateTime"/>
<xs:element name="EndTime"
            type="xs:dateTime"/>
<xs:element name="Timezone"
            type="iodef:TimezoneType"/>
<xs:simpleType name="TimezoneType">
  <xs:restriction base="xs:string">
    <xs:pattern value="Z|[\+\-](0[0-9]|1[0-4]):[0-5][0-9]"/>
  </xs:restriction>
</xs:simpleType>
<xs:element name="History">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:HistoryItem"
                  maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type" default="default"/>
  </xs:complexType>
</xs:element>
<xs:element name="HistoryItem">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:DateTime"/>
      <xs:element ref="iodef:IncidentID"
                  minOccurs="0"/>
      <xs:element ref="iodef:Contact"
                  minOccurs="0"/>
      <xs:element ref="iodef:Description"

                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
    <xs:attribute name="action"
                  type="iodef:action-type" use="required"/>
    <xs:attribute name="ext-action"
                  type="xs:string" use="optional"/>
  </xs:complexType>
</xs:element>
<xs:element name="Expectation">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:StartTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:EndTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:Contact"
                  minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type" default="default"/>
    <xs:attribute name="severity"
                  type="iodef:severity-type"/>
    <xs:attribute name="action"
                  type="iodef:action-type" default="other"/>
    <xs:attribute name="ext-action"
                  type="xs:string" use="optional"/>
  </xs:complexType>
</xs:element>
<xs:element name="Method">
  <xs:complexType>
    <xs:sequence>
      <xs:choice maxOccurs="unbounded">

        <xs:element ref="iodef:Reference"/>
        <xs:element ref="iodef:Description"/>
      </xs:choice>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="Reference">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="ReferenceName"
                  type="iodef:MLStringType"/>
      <xs:element ref="iodef:URL"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="Assessment">
  <xs:complexType>
    <xs:sequence>
      <xs:choice maxOccurs="unbounded">
        <xs:element ref="iodef:Impact"/>
        <xs:element ref="iodef:TimeImpact"/>
        <xs:element ref="iodef:MonetaryImpact"/>
      </xs:choice>
      <xs:element ref="iodef:Counter"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Confidence" minOccurs="0"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="occurrence">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="actual"/>
          <xs:enumeration value="potential"/>
        </xs:restriction>
      </xs:simpleType>

    </xs:attribute>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="Impact">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="iodef:MLStringType">
        <xs:attribute name="severity"
                      type="iodef:severity-type"/>
        <xs:attribute name="completion">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="failed"/>
              <xs:enumeration value="succeeded"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="type"
                      use="optional" default="unknown">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="admin"/>
              <xs:enumeration value="dos"/>
              <xs:enumeration value="extortion"/>
              <xs:enumeration value="file"/>
              <xs:enumeration value="info-leak"/>
              <xs:enumeration value="misconfiguration"/>
              <xs:enumeration value="recon"/>
              <xs:enumeration value="policy"/>
              <xs:enumeration value="social-engineering"/>
              <xs:enumeration value="user"/>
              <xs:enumeration value="unknown"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-type"
                      type="xs:string" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="TimeImpact">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="iodef:PositiveFloatType">

        <xs:attribute name="severity"
                      type="iodef:severity-type"/>
        <xs:attribute name="metric"
                      use="required">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="labor"/>
              <xs:enumeration value="elapsed"/>
              <xs:enumeration value="downtime"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-metric"
                      type="xs:string" use="optional"/>
        <xs:attribute name="duration"
                      type="iodef:duration-type"/>
        <xs:attribute name="ext-duration"
                      type="xs:string" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="MonetaryImpact">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="iodef:PositiveFloatType">
        <xs:attribute name="severity"
                      type="iodef:severity-type"/>
        <xs:attribute name="currency"
                      type="xs:string"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="Confidence">
  <xs:complexType mixed="true">
    <xs:attribute name="rating" use="required">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="low"/>
          <xs:enumeration value="medium"/>
          <xs:enumeration value="high"/>
          <xs:enumeration value="numeric"/>
          <xs:enumeration value="unknown"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>

  </xs:complexType>
</xs:element>
<xs:element name="EventData">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:DetectTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:StartTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:EndTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:Contact"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Assessment"
                  minOccurs="0"/>
      <xs:element ref="iodef:Method"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Flow"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Expectation"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Record"
                  minOccurs="0"/>
      <xs:element ref="iodef:EventData"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type" default="default"/>
  </xs:complexType>
</xs:element>
<xs:element name="Flow">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:System"

                  maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="System">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:Node"/>
      <xs:element ref="iodef:Service"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:OperatingSystem"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Counter"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                 type="iodef:restriction-type"/>
    <xs:attribute name="interface"
                  type="xs:string"/>
    <xs:attribute name="category">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="source"/>
          <xs:enumeration value="target"/>
          <xs:enumeration value="intermediate"/>
          <xs:enumeration value="sensor"/>
          <xs:enumeration value="infrastructure"/>
          <xs:enumeration value="ext-value"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
    <xs:attribute name="ext-category"
                  type="xs:string" use="optional"/>
    <xs:attribute name="spoofed"
                  default="unknown">
      <xs:simpleType>
        <xs:restriction base="xs:NMTOKEN">
          <xs:enumeration value="unknown"/>
          <xs:enumeration value="yes"/>

          <xs:enumeration value="no"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:attribute>
  </xs:complexType>
</xs:element>
<xs:element name="Node">
  <xs:complexType>
    <xs:sequence>
      <xs:choice maxOccurs="unbounded">
        <xs:element name="NodeName"
                    type="iodef:MLStringType" minOccurs="0"/>
        <xs:element ref="iodef:Address"
                    minOccurs="0" maxOccurs="unbounded"/>
      </xs:choice>
      <xs:element ref="iodef:Location"
                  minOccurs="0"/>
      <xs:element ref="iodef:DateTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:NodeRole"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Counter"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
<xs:element name="Address">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="xs:string">
        <xs:attribute name="category" default="ipv4-addr">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="asn"/>
              <xs:enumeration value="atm"/>
              <xs:enumeration value="e-mail"/>
              <xs:enumeration value="mac"/>
              <xs:enumeration value="ipv4-addr"/>
              <xs:enumeration value="ipv4-net"/>
              <xs:enumeration value="ipv4-net-mask"/>
              <xs:enumeration value="ipv6-addr"/>
              <xs:enumeration value="ipv6-net"/>
              <xs:enumeration value="ipv6-net-mask"/>

              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-category"
                      type="xs:string" use="optional"/>
        <xs:attribute name="vlan-name"
                      type="xs:string"/>
        <xs:attribute name="vlan-num"
                      type="xs:integer"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="Location" type="iodef:MLStringType"/>
<xs:element name="NodeRole">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="iodef:MLStringType">
        <xs:attribute name="category" use="required">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="client"/>
              <xs:enumeration value="server-internal"/>
              <xs:enumeration value="server-public"/>
              <xs:enumeration value="www"/>
              <xs:enumeration value="mail"/>
              <xs:enumeration value="messaging"/>
              <xs:enumeration value="streaming"/>
              <xs:enumeration value="voice"/>
              <xs:enumeration value="file"/>
              <xs:enumeration value="ftp"/>
              <xs:enumeration value="p2p"/>
              <xs:enumeration value="name"/>
              <xs:enumeration value="directory"/>
              <xs:enumeration value="credential"/>
              <xs:enumeration value="print"/>
              <xs:enumeration value="application"/>
              <xs:enumeration value="database"/>
              <xs:enumeration value="infra"/>
              <xs:enumeration value="log"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-category"
                      type="xs:string" use="optional"/>
      </xs:extension>

    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="Service">
  <xs:complexType>
    <xs:sequence>
      <xs:choice minOccurs="0">
        <xs:element name="Port"
                    type="xs:integer"/>
        <xs:element name="Portlist"
                    type="iodef:PortlistType"/>
      </xs:choice>
      <xs:element name="ProtoType"
                  type="xs:integer" minOccurs="0"/>
      <xs:element name="ProtoCode"
                  type="xs:integer" minOccurs="0"/>
      <xs:element name="ProtoField"
                  type="xs:integer" minOccurs="0"/>
      <xs:element ref="iodef:Application"
                  minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="ip_protocol"
                  type="xs:integer" use="required"/>
  </xs:complexType>
</xs:element>
<xs:simpleType name="PortlistType">
  <xs:restriction base="xs:string">
    <xs:pattern value="\d+(\-\d+)?(,\d+(\-\d+)?)*"/>
  </xs:restriction>
</xs:simpleType>
<xs:element name="Counter">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="xs:double">
        <xs:attribute name="type" use="required">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="byte"/>

              <xs:enumeration value="packet"/>
              <xs:enumeration value="flow"/>
              <xs:enumeration value="session"/>
              <xs:enumeration value="event"/>
              <xs:enumeration value="alert"/>
              <xs:enumeration value="message"/>
              <xs:enumeration value="host"/>
              <xs:enumeration value="site"/>
              <xs:enumeration value="organization"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-type"
                      type="xs:string" use="optional"/>
        <xs:attribute name="meaning"
                      type="xs:string" use="optional"/>
        <xs:attribute name="duration"
                      type="iodef:duration-type"/>
        <xs:attribute name="ext-duration"
                      type="xs:string" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>
<xs:element name="Record">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:RecordData"
                  maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="RecordData">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="iodef:DateTime"
                  minOccurs="0"/>
      <xs:element ref="iodef:Description"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:Application"

                  minOccurs="0"/>
      <xs:element ref="iodef:RecordPattern"
                  minOccurs="0" maxOccurs="unbounded"/>
      <xs:element ref="iodef:RecordItem"
                  maxOccurs="unbounded"/>
      <xs:element ref="iodef:AdditionalData"
                  minOccurs="0" maxOccurs="unbounded"/>
    </xs:sequence>
    <xs:attribute name="restriction"
                  type="iodef:restriction-type"/>
  </xs:complexType>
</xs:element>
<xs:element name="RecordPattern">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="xs:string">
        <xs:attribute name="type" use="required">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="regex"/>
              <xs:enumeration value="binary"/>
              <xs:enumeration value="xpath"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-type"
                      type="xs:string" use="optional"/>
        <xs:attribute name="offset"
                      type="xs:integer" use="optional"/>
        <xs:attribute name="offsetunit"
                      use="optional" default="line">
          <xs:simpleType>
            <xs:restriction base="xs:NMTOKEN">
              <xs:enumeration value="line"/>
              <xs:enumeration value="byte"/>
              <xs:enumeration value="ext-value"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:attribute>
        <xs:attribute name="ext-offsetunit"
                      type="xs:string" use="optional"/>
        <xs:attribute name="instance"
                      type="xs:integer" use="optional"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>

<xs:element name="RecordItem"
            type="iodef:ExtensionType"/>
<xs:complexType name="SoftwareType">
  <xs:sequence>
    <xs:element ref="iodef:URL"
                minOccurs="0"/>
  </xs:sequence>
  <xs:attribute name="swid"
                type="xs:string" default="0"/>
  <xs:attribute name="configid"
                type="xs:string" default="0"/>
  <xs:attribute name="vendor"
                type="xs:string"/>
  <xs:attribute name="family"
                type="xs:string"/>
  <xs:attribute name="name"
                type="xs:string"/>
  <xs:attribute name="version"
                type="xs:string"/>
  <xs:attribute name="patch"
                type="xs:string"/>
</xs:complexType>
<xs:element name="Application"
            type="iodef:SoftwareType"/>
<xs:element name="OperatingSystem"
            type="iodef:SoftwareType"/>
<xs:element name="Description"
            type="iodef:MLStringType"/>
<xs:element name="URL"
            type="xs:anyURI"/>
<xs:simpleType name="PositiveFloatType">
  <xs:restriction base="xs:float">
    <xs:minExclusive value="0"/>

  </xs:restriction>
</xs:simpleType>
<xs:complexType name="MLStringType">
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute name="lang"
                    type="xs:language" use="optional"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>
<xs:complexType name="ExtensionType" mixed="true">
  <xs:sequence>
    <xs:any namespace="##any" processContents="lax"
            minOccurs="0" maxOccurs="unbounded"/>
  </xs:sequence>
  <xs:attribute name="dtype"
                type="iodef:dtype-type" use="required"/>
  <xs:attribute name="ext-dtype"
                type="xs:string" use="optional"/>
  <xs:attribute name="meaning"
                type="xs:string"/>
  <xs:attribute name="formatid"
                type="xs:string"/>
  <xs:attribute name="restriction"
                type="iodef:restriction-type"/>
</xs:complexType>
<xs:simpleType name="restriction-type">
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="default"/>
    <xs:enumeration value="public"/>
    <xs:enumeration value="need-to-know"/>
    <xs:enumeration value="private"/>
  </xs:restriction>
</xs:simpleType>

<xs:simpleType name="severity-type">
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="low"/>
    <xs:enumeration value="medium"/>
    <xs:enumeration value="high"/>
  </xs:restriction>
</xs:simpleType>

<xs:simpleType name="duration-type">
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="second"/>
    <xs:enumeration value="minute"/>
    <xs:enumeration value="hour"/>
    <xs:enumeration value="day"/>
    <xs:enumeration value="month"/>
    <xs:enumeration value="quarter"/>
    <xs:enumeration value="year"/>
    <xs:enumeration value="ext-value"/>
  </xs:restriction>
</xs:simpleType>

<xs:simpleType name="action-type">
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="nothing"/>
    <xs:enumeration value="contact-source-site"/>
    <xs:enumeration value="contact-target-site"/>
    <xs:enumeration value="contact-sender"/>
    <xs:enumeration value="investigate"/>
    <xs:enumeration value="block-host"/>
    <xs:enumeration value="block-network"/>
    <xs:enumeration value="block-port"/>
    <xs:enumeration value="rate-limit-host"/>
    <xs:enumeration value="rate-limit-network"/>
    <xs:enumeration value="rate-limit-port"/>
    <xs:enumeration value="remediate-other"/>
    <xs:enumeration value="status-triage"/>
    <xs:enumeration value="status-new-info"/>
    <xs:enumeration value="other"/>
    <xs:enumeration value="ext-value"/>
  </xs:restriction>
</xs:simpleType>

<xs:simpleType name="dtype-type">
  <xs:restriction base="xs:NMTOKEN">
    <xs:enumeration value="boolean"/>
    <xs:enumeration value="byte"/>
    <xs:enumeration value="character"/>
    <xs:enumeration value="date-time"/>
    <xs:enumeration value="integer"/>
    <xs:enumeration value="ntpstamp"/>
    <xs:enumeration value="portlist"/>
    <xs:enumeration value="real"/>
    <xs:enumeration value="string"/>
    <xs:enumeration value="file"/>
    <xs:enumeration value="path"/>
    <xs:enumeration value="frame"/>

    <xs:enumeration value="packet"/>
    <xs:enumeration value="ipv4-packet"/>
    <xs:enumeration value="ipv6-packet"/>
    <xs:enumeration value="url"/>
    <xs:enumeration value="csv"/>
    <xs:enumeration value="winreg"/>
    <xs:enumeration value="xml"/>
    <xs:enumeration value="ext-value"/>
  </xs:restriction>
</xs:simpleType>
 </xs:schema>

Security Considerations

The IODEF data model itself does not directly introduce security issues. Rather, it simply defines a representation for incident information. As the data encoded by the IODEF might be considered privacy sensitive by the parties exchanging the information or by those described by it, care needs to be taken in ensuring the appropriate disclosure during both document exchange and subsequent processing. The former must be handled by a messaging format, but the latter risk must be addressed by the systems that process, store, and archive IODEF documents and information derived from them.

The contents of an IODEF document may include a request for action or an IODEF parser may independently have logic to take certain actions based on information that it finds. For this reason, care must be taken by the parser to properly authenticate the recipient of the document and ascribe an appropriate confidence to the data prior to action.

The underlying messaging format and protocol used to exchange instances of the IODEF MUST provide appropriate guarantees of confidentiality, integrity, and authenticity. The use of a standardized security protocol is encouraged. The Real-time Inter- network Defense (RID) protocol [18] and its associated transport binding IODEF/RID over SOAP [19] provide such security.

In order to suggest data processing and handling guidelines of the encoded information, the IODEF allows a document sender to convey a privacy policy using the restriction attribute. The various instances of this attribute allow different data elements of the document to be covered by dissimilar policies. While flexible, it must be stressed that this approach only serves as a guideline from the sender, as the recipient is free to ignore it. The issue of enforcement is not a technical problem.

10. IANA Considerations

This document uses URNs to describe an XML namespace and schema conforming to a registry mechanism described in [15]

Registration for the IODEF namespace:

o URI: urn:ietf:params:xml:ns:iodef-1.0

o Registrant Contact: See the first author of the "Author's Address"

  section of this document.

o XML: None. Namespace URIs do not represent an XML specification.

Registration for the IODEF XML schema:

o URI: urn:ietf:params:xml:schema:iodef-1.0

o Registrant Contact: See the first author of the "Author's Address"

  section of this document.

o XML: See the "IODEF Schema" in Section 8 of this document.

11. Acknowledgments

The following groups and individuals, listed alphabetically, contributed substantially to this document and should be recognized for their efforts.

o Patrick Cain, Cooper-Cain Group, Inc.

o The eCSIRT.net Project

o The Incident Object Description and Exchange Format Working-Group

  of the TERENA task-force (TF-CSIRT)

o Glenn Mansfield Keeni, Cyber Solutions, Inc.

o Hiroyuki Kido, NARA Institute of Science and Technology

o Kathleen Moriarty, MIT Lincoln Laboratory

o Brian Trammell, CERT/NetSA

12. References

12.1. Normative References

[1] World Wide Web Consortium, "Extensible Markup Language (XML)

     1.0 (Second Edition)", W3C Recommendation , October 2000,
     <http://www.w3.org/TR/2000/REC-xml-20001006>.

[2] World Wide Web Consortium, "XML XML Schema Part 1: Structures

     Second Edition", W3C Recommendation , October 2004,
     <http://www.w3.org/TR/xmlschema-1/>.

[3] World Wide Web Consortium, "XML Schema Part 2: Datatypes Second

     Edition", W3C Recommendation , October 2004,
     <http://www.w3.org/TR/xmlschema-2/>.

[4] World Wide Web Consortium, "Namespaces in XML", W3C

     Recommendation , January 1999,
     <http://www.w3.org/TR/REC-xml-names/>.

[5] World Wide Web Consortium, "XML Path Language (XPath) 2.0", W3C

     Candidate Recommendation , June 2006,
     <http://www.w3.org/TR/xpath20/>.

[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement

     Levels", RFC 2119, March 1997.

[7] Philips, A. and M. Davis, "Tags for Identifying of Languages",

     RFC 4646, September 2006.

[8] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform

     Resource Identifiers (URI): Generic Syntax", RFC 3986,
     January 2005`.

[9] Freed, N. and J. Postel, "IANA Charset Registration

     Procedures", BCP 2978, October 2000.

[10] Sciberras, A., "Schema for User Applications", RFC 4519,

     June 2006.

[11] Resnick, P., "Internet Message Format", RFC 2822, April 2001.

[12] Klyne, G. and C. Newman, "Date and Time on the Internet:

     Timestamps", RFC 3339, July 2002.

[13] International Organization for Standardization, "International

     Standard: Data elements and interchange formats - Information
     interchange - Representation of dates and times", ISO 8601,
     Second Edition, December 2000.

[14] International Organization for Standardization, "International

     Standard: Codes for the representation of currencies and funds,
     ISO 4217:2001", ISO 4217:2001, August 2001.

[15] Mealling, M., "The IETF XML Registry", RFC 3688, January 2004.

12.2. Informative References

[16] Keeni, G., Demchenko, Y., and R. Danyliw, "Requirements for the

     Format for Incident Information Exchange (FINE)", Work
     in Progress, June 2006.

[17] Debar, H., Curry, D., Debar, H., and B. Feinstein, "Intrusion

     Detection Message Exchange Format", RFC 4765, March 2007.

[18] Moriarty, K., "Real-time Inter-network Defense", Work

     in Progress, April 2007.

[19] Moriarty, K. and B. Trammell, "IODEF/RID over SOAP", Work

     in Progress, April 2007.

[20] Shafranovich, Y., "Common Format and MIME Type for Comma-

     Separated Values (CSV) File", RFC 4180, October 2005.

Authors' Addresses

Roman Danyliw CERT - Software Engineering Institute Pittsburgh, PA USA

EMail: [email protected]

Jan Meijer

EMail: [email protected]

Yuri Demchenko University of Amsterdam Amsterdam Netherlands

EMail: [email protected]

Full Copyright Statement

This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.

This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at [email protected].

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RFC5070

Contents

Introduction

Terminology

Notations

About the IODEF Data Model

About the IODEF Implementation

IODEF Data Types

Integers

Real Numbers

Characters and Strings

Multilingual Strings

Bytes

Hexadecimal Bytes

Enumerated Types

Date-Time Strings

Timezone String

The IODEF Data Model

IODEF-Document Class

Incident Class

IncidentID Class

AlternativeID Class

RelatedActivity Class

AdditionalData Class

Contact Class

RegistryHandle Class

PostalAddress Class

Email Class

Telephone and Fax Classes

Time Classes

StartTime

EndTime

DetectTime

ReportTime

DateTime

Method Class

Reference Class

Processing Considerations

Encoding

IODEF Namespace

Validation

Extending the IODEF

Extending the Enumerated Values of Attributes

Extending Classes

Internationalization Issues

Examples

Worm

Reconnaissance

Bot-Net Reporting

Watch List

The IODEF Schema

Security Considerations

Navigation

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