Multiple users forwarding O365 mail to same destination
This query over Office Activity audit data highlights cases where user mail is being forwarded.
Source: Github - Microsoft
MITRE ATT&CK Tactics
Review the affected O365 email accounts and destination email address.
Review SENT email content to understand if any attachments (confidential data) was sent out of organization.
Evaluate if destination email address is on any Threat Intelligence list.
Remove forwarder from Office 365 Admin Exchange