GitHub User Unblocked From Accessing Organization Repositories

// Copyright 2024 Google LLC. Licensed under Apache-2.0.

rule github_user_unblocked_from_accessing_organization_repositories {

  meta:
    author = "Google Cloud Security"
    description = "Detects when a user is unblocked from accessing repositories within a GitHub organization."
    rule_id = "mr_3a6905e8-e5e1-40af-b911-52bc4918d2ba"
    rule_name = "GitHub User Unblocked From Accessing Organization Repositories"
    assumption = "Your GitHub enterprise audit log settings are configured to log the source IP address for events. Reference: https://docs.github.com/en/organizations/keeping-your-organization-secure/managing-security-settings-for-your-organization/displaying-ip-addresses-in-the-audit-log-for-your-organization"
    type = "alert"
    severity = "Low"
    priority = "Low"
    platform = "GitHub"
    data_source = "github"
    reference = "https://docs.github.com/en/enterprise-cloud@latest/admin/monitoring-activity-in-your-enterprise/reviewing-audit-logs-for-your-enterprise/audit-log-events-for-your-enterprise"

  events:
    $github.metadata.vendor_name = "GITHUB" nocase
    $github.metadata.product_name = "GITHUB"
    $github.metadata.product_event_type = "org.unblock_user"
    $github.principal.user.userid = $actor_user_id
    $github.extracted.fields["blocked_user"] = $target_user_id

  match:
    $actor_user_id, $target_user_id over 30m

  outcome:
    $risk_score = max(35)
    $event_count = count_distinct($github.metadata.id)
    $principal_ip = array_distinct($github.principal.ip)
    $principal_user_userid = array_distinct($github.principal.user.userid)
    $principal_ip_country = array_distinct($github.principal.ip_geo_artifact.location.country_or_region)
    $principal_ip_state = array_distinct($github.principal.ip_geo_artifact.location.state)
    $principal_ip_city = array_distinct($github.principal.location.city)
    $security_result_summary = array_distinct($github.security_result.summary)

  condition:
    $github
}