Malicious Office 365 Email Forwarding Rule to External Domain (via office365)
- Product
- azure
- Service
- office365
- Author
- HuntRule
- Published
- 2026-05-14
- Updated
- 2026-08-28
ATT&CK techniques
CollectionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects creates a forwarding rules to a non company email in order to collect information.
Reporting behind it
- attack.mitre.orghttps://attack.mitre.org/techniques/T1114/003/
- redcanary.comhttps://redcanary.com/blog/email-forwarding-rules/
- raw.githubusercontent.comhttps://raw.githubusercontent.com/PwC-IR/Business-Email-Compromise-Guide/main/PwC-Business_Email_Compromise-Guide.pdf
- docs.microsoft.comhttps://docs.microsoft.com/en-us/microsoft-365/security/defender/alert-grading-playbook-email-forwarding?view=o365-worldwide
- logrhythm.comhttps://logrhythm.com/blog/detecting-and-preventing-auto-forwarding-and-phishing-attacks-in-office-365/
- microsoft.comhttps://www.microsoft.com/en-us/security/blog/2023/06/08/detecting-and-mitigating-a-multi-stage-aitm-phishing-and-bec-campaign/
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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