Detection rules › YARA-L

Google Workspace Admin Role Assignment

Severity
high
Type
Alert
Author
Google Cloud Security
Source
github.com/chronicle/detection-rules

Identifies when an administrator role is assigned to a user account in Google Workspace. Security teams can monitor for the malicious or accidental assignment of administrator privileges to prevent unauthorized access to data.

MITRE ATT&CK coverage

Telemetry coverage

PlatformRecord / event type
Google WorkspaceASSIGN_ROLE: Assign Role

Rules detecting the same action

These rules filter on the same operation.

Rule body

// Copyright 2023 Google LLC. Licensed under Apache-2.0.

rule google_workspace_admin_role_assignment {

  meta:
    author = "Google Cloud Security"
    description = "Identifies when an administrator role is assigned to a user account in Google Workspace. Security teams can monitor for the malicious or accidental assignment of administrator privileges to prevent unauthorized access to data."
    rule_id = "mr_0c547820-1095-42a1-94d8-a00d5ef2df76"
    rule_name = "Google Workspace Admin Role Assignment"
    mitre_attack_tactic = "Persistence"
    mitre_attack_technique = "Account Manipulation: Additional Cloud Roles"
    mitre_attack_url = "https://attack.mitre.org/techniques/T1098/003/"
    mitre_attack_version = "v13.1"
    type = "Alert"
    data_source = "Workspace Activity"
    severity = "High"
    priority = "High"

  events:
    $ws.metadata.vendor_name = "Google Workspace"
    $ws.metadata.product_name = "admin"
    $ws.metadata.event_type = "USER_RESOURCE_UPDATE_PERMISSIONS"
    $ws.metadata.product_event_type = "ASSIGN_ROLE"
    $ws.security_result.category_details = "DELEGATED_ADMIN_SETTINGS"

  outcome:
    $risk_score = max(35 +
        if($ws.target.resource.attribute.roles.name = "_SEED_ADMIN_ROLE", 50)
    )
    $mitre_attack_tactic = "Persistence"
    $mitre_attack_technique = "Account Manipulation: Additional Cloud Roles"
    $mitre_attack_technique_id = "T1098.003"
    $event_count = count_distinct($ws.metadata.id)
    $principal_ip = array_distinct($ws.principal.ip)
    $principal_country = array_distinct($ws.principal.ip_geo_artifact.location.country_or_region)
    $principal_state = array_distinct($ws.principal.ip_geo_artifact.location.state)
    $principal_user_emails = array_distinct($ws.principal.user.email_addresses)
    $target_user_emails = array_distinct($ws.target.user.email_addresses)
    $principal_user_id = $ws.principal.user.userid
    $role_name = array_distinct($ws.target.resource.attribute.roles.name)

  condition:
    $ws
}

YARA-L rule structure

Condition

Fires when at least one $ws event.

Events

$ws USER_RESOURCE_UPDATE_PERMISSIONS

  • metadata.product_event_type = "ASSIGN_ROLE"
  • security_result.category_details = "DELEGATED_ADMIN_SETTINGS"

Outcome

Outcome variables add context to a detection. When the rule generates an alert, $risk_score is displayed with it.

FieldExpression
risk_scoremax(35 + if($ws.target.resource.attribute.roles.name = "_SEED_ADMIN_ROLE", 50) )
event_countcount_distinct($ws.metadata.id)
principal_iparray_distinct($ws.principal.ip)
principal_countryarray_distinct($ws.principal.ip_geo_artifact.location.country_or_region)
principal_statearray_distinct($ws.principal.ip_geo_artifact.location.state)
principal_user_emailsarray_distinct($ws.principal.user.email_addresses)
target_user_emailsarray_distinct($ws.target.user.email_addresses)
principal_user_id$ws.principal.user.userid
role_namearray_distinct($ws.target.resource.attribute.roles.name)