name: GitHub Pull Request from Unknown User
id: 9d7b9100-8878-4404-914e-ca5e551a641e
version: 1
date: '2021-09-01'
author: Patrick Bareiss, Splunk
status: production
type: Anomaly
description: This search looks for Pull Request from unknown user.
data_source: []
search: '`github` check_suite.pull_requests{}.id=* | stats count by check_suite.head_commit.author.name
  repository.full_name check_suite.pull_requests{}.head.ref check_suite.head_commit.message
  | rename check_suite.head_commit.author.name as user repository.full_name as repository
  check_suite.pull_requests{}.head.ref as ref_head check_suite.head_commit.message
  as commit_message | search NOT `github_known_users` | eval phase="code" | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `github_pull_request_from_unknown_user_filter`'
how_to_implement: You must index GitHub logs. You can follow the url in reference
  to onboard GitHub logs.
known_false_positives: unknown
references:
- https://www.splunk.com/en_us/blog/tips-and-tricks/getting-github-data-with-webhooks.html
tags:
  analytic_story:
  - Dev Sec Ops
  asset_type: GitHub
  confidence: 90
  impact: 30
  message: Vulnerabilities found in packages used by GitHub repository $repository$
  mitre_attack_id:
  - T1195.001
  - T1195
  observable:
  - name: repository
    type: Unknown
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - alert.id
  - repository.full_name
  - repository.html_url
  - action
  - alert.affected_package_name
  - alert.affected_range
  - alert.created_at
  - alert.external_identifier
  - alert.external_reference
  - alert.fixed_in
  - alert.severity
  risk_score: 27
  security_domain: network
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1195.001/github_pull_request/github_pull_request.json
    sourcetype: aws:firehose:json
    source: github