ASL AWS Multi-Factor Authentication Disabled

name: ASL AWS Multi-Factor Authentication Disabled
id: 4d2df5e0-1092-4817-88a8-79c7fa054668
version: 10
date: '2026-03-10'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages Amazon Security Lake logs, specifically monitoring for `DeleteVirtualMFADevice` or `DeactivateMFADevice` API operations. This activity is significant as disabling MFA can indicate an adversary attempting to weaken account security to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, potentially leading to unauthorized access to sensitive resources and prolonged compromise.
data_source:
    - ASL AWS CloudTrail
search: |-
    `amazon_security_lake` (api.operation=DeleteVirtualMFADevice OR api.operation=DeactivateMFADevice)
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY actor.user.uid api.operation api.service.name
           http_request.user_agent src_endpoint.ip actor.user.account.uid
           cloud.provider cloud.region
      | rename actor.user.uid as user api.operation as action api.service.name as dest http_request.user_agent as user_agent src_endpoint.ip as src actor.user.account.uid as vendor_account cloud.provider as vendor_product cloud.region as vendor_region
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `asl_aws_multi_factor_authentication_disabled_filter`
how_to_implement: The detection is based on Amazon Security Lake events from Amazon Web Services (AWS), which is a centralized data lake that provides security-related data from AWS services. To use this detection, you must ingest CloudTrail logs from Amazon Security Lake into Splunk. To run this search, ensure that you ingest events using the latest version of Splunk Add-on for Amazon Web Services (https://splunkbase.splunk.com/app/1876) or the Federated Analytics App.
known_false_positives: AWS Administrators may disable MFA but it is highly unlikely for this event to occur without prior notice to the company
references:
    - https://attack.mitre.org/techniques/T1621/
    - https://aws.amazon.com/what-is/mfa/
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 $user$ has disabled Multi-Factor authentication
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src
          type: ip_address
tags:
    analytic_story:
        - AWS Identity and Access Management Account Takeover
    asset_type: AWS Account
    mitre_attack_id:
        - T1556.006
        - T1586.003
        - T1621
    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/T1621/aws_mfa_disabled/asl_ocsf_cloudtrail.json
          sourcetype: aws:asl
          source: aws_asl