Microsoft 365 Audit: Disabling Strong Authentication (MFA)

Flags Microsoft 365 audit events indicating MFA/strong authentication was disabled.

FreeReviewedSigma · High · v4
Product
m365
Service
audit
Author
Splunk Threat Research Team (original rule), Harjot Singh @cyb3rjy0t (sigma rule) (SigmaHQ), DRL 1.1
Published
2023-09-18
Updated
2026-07-31
title: "Microsoft 365 Audit: Disabling Strong Authentication (MFA)"
id: 13099bbb-ec46-4eb3-95c6-ad3b1dd5f9a5
status: test
description: This rule matches Microsoft 365 audit events where the operation contains 'Disable Strong Authentication,' indicating MFA/strong authentication has been turned off. Disabling MFA weakens account protections and can enable attackers to maintain access with stolen credentials. It relies on Microsoft 365 audit/service telemetry capturing the specific operation string.
references:
  - https://research.splunk.com/cloud/c783dd98-c703-4252-9e8a-f19d9f5c949e/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/m365/audit/microsoft365_disabling_mfa.yml
author: Splunk Threat Research Team (original rule), Harjot Singh @cyb3rjy0t (sigma rule), Huntrule Team
date: 2023-09-18
tags:
  - attack.persistence
  - attack.credential-access
  - attack.defense-impairment
  - attack.t1556.006
logsource:
  service: audit
  product: m365
detection:
  selection:
    Operation|contains: Disable Strong Authentication.
  condition: selection
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 60de9b57-dc4d-48b9-a6a0-b39e0469f876
    type: derived