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M365 Exchange Inbox Phishing Evasion Rule Created

Identifies when a user creates a new inbox rule in Microsoft 365 that deletes or moves emails containing suspicious keywords. Adversaries who have compromised accounts often create inbox rules to hide alerts,…

Description

Identifies when a user creates a new inbox rule in Microsoft 365 that deletes or moves emails containing suspicious keywords. Adversaries who have compromised accounts often create inbox rules to hide alerts, security notifications, or other sensitive messages by automatically deleting them or moving them to obscure folders. Common destinations include Deleted Items, Junk Email, RSS Feeds, and RSS Subscriptions. This is a New Terms rule that triggers only when the user principal name and associated source IP address have not been observed performing this activity in the past 14 days.

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
ESXiLinuxmacOSOffice SuiteWindows

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

Log source category
event_index

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