splunk_escuTTP

O365 Disable MFA

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.

MITRE ATT&CK

T1556

Detection Query

`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`

Author

Rod Soto, Splunk

Created

2026-03-10

Data Sources

O365 Disable Strong Authentication.

References

https://attack.mitre.org/techniques/T1556/

Tags

Office 365 Persistence Mechanisms

Raw Content

name: O365 Disable MFA
id: c783dd98-c703-4252-9e8a-f19d9f5c949e
version: 9
date: '2026-03-10'
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/
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168  | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: User $src_user$ has executed an operation $signature$ for user $user$
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - Office 365 Persistence Mechanisms
    asset_type: O365 Tenant
    mitre_attack_id:
        - T1556
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1556/o365_disable_mfa/o365_disable_mfa.json
          sourcetype: o365:management:activity
          source: o365