Back to results

M365 Exchange Mail Flow Transport Rule Created

Identifies a transport rule creation in Microsoft 365. As a best practice, Exchange Online mail transport rules should not be set to forward email to domains outside of your organization. An adversary may create…

Description

Identifies a transport rule creation in Microsoft 365. As a best practice, Exchange Online mail transport rules should not be set to forward email to domains outside of your organization. An adversary may create transport rules to exfiltrate data.

Detection logic

Its licence does not clear it for publishing here

Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.

Detection requirements

Platform
IaaSLinuxmacOSOffice SuiteSaaSWindows

The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.

Log source category
event_index

Known benign triggers

  • A new transport rule may be created by a system or network administrator. Verify that the configuration change was expected. Exceptions can be added to this rule to filter expected behavior.

Detections can measure how the public catalogue is used — which detections people look for, and which pages bring them here. It sets a cookie that recognises this browser for 180 days. It is never linked to an account and never follows you to other sites. Privacy notice