AWS Multi-Factor Authentication Disabled

SPLUNK detection rule by Bhavin Patel, Splunk · Apache-2.0

The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages AWS CloudTrail logs to identify events where MFA devices are deleted or deactivated. This activity is significant because disabling MFA can indicate an adversary attempting to weaken account security, potentially to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, posing a significant risk to the security and integrity of the cloud infrastructure.

name: AWS Multi-Factor Authentication Disabled
id: 374832b1-3603-420c-b456-b373e24d34c0
version: 12
creation_date: '2022-10-04'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: production
type: TTP
description: The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages AWS CloudTrail logs to identify events where MFA devices are deleted or deactivated. This activity is significant because disabling MFA can indicate an adversary attempting to weaken account security, potentially to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, posing a significant risk to the security and integrity of the cloud infrastructure.
data_source:
    - AWS CloudTrail DeleteVirtualMFADevice
    - AWS CloudTrail DeactivateMFADevice
search: |-
    `cloudtrail` (eventName= DeleteVirtualMFADevice OR eventName=DeactivateMFADevice)
      | rename user_name as user
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature dest user
           user_agent src vendor_account
           vendor_region vendor_product
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `aws_multi_factor_authentication_disabled_filter`
how_to_implement: The Splunk AWS Add-on is required to utilize this data. The search requires AWS CloudTrail logs.
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 - "$vendor_account$" and "$user$"
      search: '%original_detection_search% | search  vendor_account = "$vendor_account$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$vendor_account$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$vendor_account$", "$user$") | 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: 7d
      latest_offset: "0"
finding:
    title: User $user$ has disabled Multi-Factor authentication for AWS account $vendor_account$
    entity:
        field: user
        type: user
        score: 50
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - AWS Identity and Access Management Account Takeover
    - Scattered Lapsus$ Hunters
asset_type: AWS Account
mitre_attack_id:
    - T1556.006
    - T1586.003
    - T1621
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: 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/cloudtrail.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail
      test_type: unit

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67b04b55-c7b5-4a35-a87b-cc1a115e798c

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