# 0018: Extend Threat Fieldset
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- Stage: **3 (finished)** <!-- Update to reflect target stage. See https://elastic.github.io/ecs/stages.html -->
- Date: **2021-07-28** <!-- The ECS team sets this date at merge time. This is the date of the latest stage advancement. -->

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Stage 0: Provide a high level summary of the premise of these changes. Briefly describe the nature, purpose, and impact of the changes. ~2-5 sentences.
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Currently the `threat` fieldset includes tactic, technique, and sub-techniques from the ATT&CK framework. ATT&CK also includes groups and software that we can easily add to the existing fieldset to include all of the ATT&CK framework. While these fields are directly referenced within the ATT&CK framework, they can also be used with other frameworks if `threat.framework` expands to use more than ATT&CK.

## Fields

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### Proposed New Fields for Threat fieldset

Field | Type | Example | Description
--- | --- | --- | ---
threat.software.id | keyword | S0023 | The id of the software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software id.
threat.software.name | keyword | CHOPSTICK | The name of the software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software name.
threat.software.alias | keyword | X-Agent | The name of the software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software name.
threat.software.platforms | keyword | Windows | The platforms of the software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software platforms.
threat.software.reference | keyword | https://attack.mitre.org/software/S0023/ | The reference URL of the software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software reference URL.
threat.software.type | keyword | Malware | The type of software used by this threat to conduct behavior commonly modeled using MITRE ATT&CK®. While not required, you can use a MITRE ATT&CK® software type.
threat.group.alias | keyword | FIN6, ITG08, Magecart Group 6, etc | The alias(es) of the group for a set of related intrusion activity that are tracked by a common name in the security community. While not required, you can use a MITRE ATT&CK® group alias(es).
threat.group.id | keyword | G0037 | The id of the group for a set of related intrusion activity that are tracked by a common name in the security community. While not required, you can use a MITRE ATT&CK® group id.
threat.group.name | keyword | FIN6 | The name of the group for a set of related intrusion activity that are tracked by a common name in the security community. While not required, you can use a MITRE ATT&CK® group name.
threat.group.reference | keyword | https://attack.mitre.org/groups/G0037/ | The reference URL of the group for a set of related intrusion activity that are tracked by a common name in the security community. While not required, you can use a MITRE ATT&CK® group reference URL.

## Usage

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Stage 1: Describe at a high-level how these field changes will be used in practice. Real world examples are encouraged. The goal here is to understand how people would leverage these fields to gain insights or solve problems. ~1-3 paragraphs.
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These fields can be used to associate fields that already exist in the `threat.*` fieldset, such as tactic, technique, and sub-technique. ATT&CK has relationships built within their framework for software and groups as it relates to tactic, technique, and sub-techniques. This information will provide for a more enriched threat profile for indicators and events.

Currently, tactic, technique, and sub-techniques are also included in rules for the Detection Engine, adding software and groups would make for more contextually relevant alerts that could aid in analysis and response operations.

**Existing threat fields**
```json
{
    "threat.framework": "ATT&CK",
    "threat.tactic.id": "TA0007",
    "threat.tactic.name": "Discovery",
    "threat.tactic.reference": "https://attack.mitre.org/tactics/TA0007/",
    "threat.technique.id": "T1087",
    "threat.technique.name": "Account Discovery",
    "threat.technique.reference": "https://attack.mitre.org/techniques/T1087/",
    "threat.technique.subtechnique.id": "T1087.002",
    "threat.technique.subtechnique.name": "Domain Account",
    "threat.technique.subtechnique.reference": "https://attack.mitre.org/techniques/T1087/002/"
}
```
**New Software fields**
```json
{
    "threat.software.id": "S0023",
    "threat.software.name": "CHOPSTICK",
    "threat.software": {
      "alias": [
        "Backdoor.SofacyX",
        "SPLM",
        "Xagent",
        "X-Agent",
        "webhp"
      ]
    },
    "threat.software": {
      "platforms": [
        "Windows",
        "Linux"
      ]
    },
    "threat.software.reference": "https://attack.mitre.org/software/S0023/",
    "threat.software.type": "Malware"
}
```
**New Group fields**
```json
{
    "threat.group": {
      "alias": [
        "FIN6",
        "Magecart Group 6",
        "SKELETON SPIDER",
        "ITG08"
      ]
    },
    "threat.group.id": "G0037",
    "threat.group.name": "FIN6",
    "threat.group.reference": "https://attack.mitre.org/groups/G0037/"
}
```

## Source data

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The data can come from MITRE ATT&CK, which includes the software and group information outlined in the RFC.

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Examples are from MITRE's [enterprise matrix](https://github.com/mitre/cti/blob/master/enterprise-attack/enterprise-attack.json).

**Software Source Data**
```json
{
    "external_references": [
        {
            "external_id": "S0552",
            "url": "https://attack.mitre.org/software/S0552"
        }
    ],
    "name": "AdFind",
    "type": "tool",
    "x_mitre_platforms": [
        "Windows"
    ]
}
```
```json
{
    "external_references": [
        {
            "external_id": "S0369",
            "url": "https://attack.mitre.org/software/S0369"
        }
    ],
    "name": "CoinTicker",
    "type": "malware",
    "x_mitre_platforms": [
        "macOS"
    ]
}
```
```json
{
    "external_references": [
        {
            "external_id": "S0023",
            "url": "https://attack.mitre.org/software/S0023"
        }
    ],
    "name": "CHOPSTICK",
    "type": "malware",
    "x_mitre_platforms": [
        "Linux"
    ]
}
```
**Group Source Data**
```json
{
    "name": "FIN6",
    "external_references": [
        {
            "url": "https://attack.mitre.org/groups/G0037",
            "external_id": "G0037"
        }
    ],
    "aliases": [
        "FIN6",
        "Magecart Group 6",
        "SKELETON SPIDER",
        "ITG08"
    ],
}
```
```json
{
    "name": "Putter Panda",
    "external_references": [
        {
            "url": "https://attack.mitre.org/groups/G0024",
            "external_id": "G0024"
        }
    ],
    "aliases": [
        "APT2",
        "MSUpdater"
    ],
}
```
```json
{
    "name": "Darkhotel",
    "external_references": [
        {
            "url": "https://attack.mitre.org/groups/G0012",
            "external_id": "G0012"
        }
    ],
    "aliases": [
        "DUBNIUM"
    ],
}
```

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## Scope of impact

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## Concerns

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**MITRE ATT&CK**

The MITRE ATT&CK Matrix provides the material used in these examples. While ATT&CK may be the most widely known source organized in this manner, it is neither the only source of this data or the required source.

To resolve this, we adjusted the descriptions with the following (where applicable):

- `...While not required, you can use a MITRE ATT&CK® {software,group} {field}.`
  - Example: `While not required, you can use a MITRE ATT&CK® software platform.`
- `Recommended Values:` from `Expected Values:`
  - Example:
  ```
  Recommended Values:
    * AWS
    * Azure
    ...
  ```

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## People

The following are the people that consulted on the contents of this RFC.

* @peasead | author, subject matter expert
* @devonakerr | sponsor
* @dcode | subject matter expert

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## References

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- [AdFind Software](https://attack.mitre.org/software/S0552/)
- [CoinTicker](https://attack.mitre.org/software/S0369)
- [CHOPSTICK](https://attack.mitre.org/software/S0023)
- [FIN6 Group](https://attack.mitre.org/groups/G0037/)
- [Putter Panda](https://attack.mitre.org/groups/G0024)
- [DarkHotel](https://attack.mitre.org/groups/G0012)
- [Discovery Tactic](https://attack.mitre.org/tactics/TA0007/)
- [Account Discovery Technique](https://attack.mitre.org/techniques/T1087/)
- [Account Discovery: Domain Account Sub Technique](https://attack.mitre.org/techniques/T1087/002/)

### RFC Pull Requests

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* Stage 0: https://github.com/elastic/ecs/pull/1300
* Stage 1: https://github.com/elastic/ecs/pull/1335
* Stage 2: https://github.com/elastic/ecs/pull/1395
    * Stage 2 advancement date correction: https://github.com/elastic/ecs/pull/1429
* Stage 3: https://github.com/elastic/ecs/pull/1442

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