LoFP LoFP / administrators may create custom email routes in google workspace based on organizational policies, administrative preference or for security purposes regarding spam.

Techniques

Sample rules

Google Workspace Custom Gmail Route Created or Modified

Description

Detects 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.

Detection logic

event.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")