Google Workspace Custom Gmail Route Created or Modified
editGoogle Workspace Custom Gmail Route Created or Modified
editDetects when a custom Gmail route is added or modified in Google Workspace. Adversaries can add a custom e-mail route for outbound mail to route these e-mails to their own inbox of choice for data gathering. This allows adversaries to capture sensitive information from e-mail and potential attachments, such as invoices or payment documents. By default, all email from current Google Workspace users with accounts are routed through a domain’s mail server for inbound and outbound mail.
Rule type: query
Rule indices:
- filebeat-*
- logs-google_workspace*
Severity: medium
Risk score: 47
Runs every: 10m
Searches indices from: now-130m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Cloud
- Google Workspace
- Continuous Monitoring
- SecOps
- Collection
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit### Important Information Regarding Google Workspace Event Lag Times - As per Google's documentation, Google Workspace administrators may observe lag times ranging from minutes up to 3 days between the time of an event's occurrence and the event being visible in the Google Workspace admin/audit logs. - This rule is configured to run every 10 minutes with a lookback time of 130 minutes. - To reduce the risk of false negatives, consider reducing the interval that the Google Workspace (formerly G Suite) Filebeat module polls Google's reporting API for new events. - By default, `var.interval` is set to 2 hours (2h). Consider changing this interval to a lower value, such as 10 minutes (10m). - See the following references for further information: - https://support.google.com/a/answer/7061566 - https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-module-google_workspace.html
Rule query
editevent.dataset:"google_workspace.admin" and event.action:("CREATE_GMAIL_SETTING" or "CHANGE_GMAIL_SETTING")
and google_workspace.event.type:"EMAIL_SETTINGS" and google_workspace.admin.setting.name:("EMAIL_ROUTE" or "MESSAGE_SECURITY_RULE")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Collection
- ID: TA0009
- Reference URL: https://attack.mitre.org/tactics/TA0009/
-
Technique:
- Name: Email Collection
- ID: T1114
- Reference URL: https://attack.mitre.org/techniques/T1114/
-
Sub-technique:
- Name: Email Forwarding Rule
- ID: T1114.003
- Reference URL: https://attack.mitre.org/techniques/T1114/003/