O365 Disable MFA

name: O365 Disable MFA
id: c783dd98-c703-4252-9e8a-f19d9f5c949e
version: 11
creation_date: '2020-12-16'
modification_date: '2026-05-13'
author: Rod Soto, Splunk
status: production
type: TTP
description: The following analytic identifies instances where Multi-Factor Authentication (MFA) is disabled for a user within the Office 365 environment. It leverages O365 audit logs, specifically focusing on events related to MFA settings. Disabling MFA removes a critical security layer, making accounts more vulnerable to unauthorized access. If confirmed malicious, this activity could indicate an attacker attempting to maintain persistence or an insider threat, significantly increasing the risk of unauthorized access. Immediate investigation is required to validate the reason for disabling MFA, potentially re-enable it, and assess any other suspicious activities related to the affected account.
data_source:
    - O365 Disable Strong Authentication.
search: |-
    `o365_management_activity` Operation="Disable Strong Authentication."
      | rename UserId as user object as src_user
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature dest user
           src vendor_account vendor_product
           src_user
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `o365_disable_mfa_filter`
how_to_implement: You must install the Splunk Microsoft Office 365 add-on. This search works with o365:management:activity
known_false_positives: Unless it is a special case, it is uncommon to disable MFA or Strong Authentication
references:
    - https://attack.mitre.org/techniques/T1556/
finding:
    title: User $src_user$ has executed an operation $signature$ for user $user$
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Office 365 Persistence Mechanisms
asset_type: O365 Tenant
mitre_attack_id:
    - T1556
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat