Threat Essentials - Mail redirect via ExO transport rule
Identifies when Exchange Online transport rule configured to forward emails. This could be an adversary mailbox configured to collect mail from multiple user accounts.
Detection logic
Detection requirements
- Platform
- LinuxmacOSNetwork DevicesOffice SuiteWindows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
- Log source product
- office365
- Log source service
- officeactivity
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
No references are available for this detection.
From the source
- At source
- Open at source
- Upstream identifier
- d7c575b2-84f5-48cb-92c5-70d7e8246284
- Tagged by the source as
- CollectionExfiltration
Licence
- Published under
- MIT LicenseRead the licence
- Attribution
- Required
- Obtained under
- MITRead the origin licence
Authorship
- Published
- Sep 1, 2026
- Version
- 1