Microsoft Cloud App Security Activity by Terminated Azure AD User

Alerts on successful "Activity performed by terminated user" events where a terminated Azure AD account still shows activity.

FreeReviewedSigma · Medium · v4
Product
m365
Service
threat_management
Author
Austin Songer @austinsonger (SigmaHQ), DRL 1.1
Published
2021-08-23
Updated
2026-07-31
title: Microsoft Cloud App Security Activity by Terminated Azure AD User
id: ade732a0-e135-4483-aad6-4f6d1e9ab000
status: test
description: This rule identifies successful "Activity performed by terminated user" events reported by Microsoft Cloud App Security for accounts marked as terminated in Azure AD. Attackers may retain access via alternate identities or continue using an offboarded account to interact with other cloud services, so these events can indicate account lifecycle abuse. The detection relies on threat-management telemetry that includes the event source, event name, and success status from the reporting system.
references:
  - https://learn.microsoft.com/en-us/defender-cloud-apps/anomaly-detection-policy
  - https://learn.microsoft.com/en-us/defender-cloud-apps/policy-template-reference
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/m365/threat_management/microsoft365_activity_by_terminated_user.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-23
modified: 2022-10-09
tags:
  - attack.impact
logsource:
  service: threat_management
  product: m365
detection:
  selection:
    eventSource: SecurityComplianceCenter
    eventName: Activity performed by terminated user
    status: success
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 2e669ed8-742e-4fe5-b3c4-5a59b486c2ee
    type: derived