Name:GCP Multi-Factor Authentication Disabled id:b9bc5513-6fc1-4821-85a3-e1d81e451c83 version:4 date:2024-09-30 author:Bhavin Patel, Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic detects an attempt to disable multi-factor authentication (MFA) for a Google Cloud Platform (GCP) user. It leverages Google Workspace Admin log events, specifically the `UNENROLL_USER_FROM_STRONG_AUTH` command. This activity is significant because disabling MFA can allow an adversary to maintain persistence within the environment using a compromised account without raising suspicion. If confirmed malicious, this action could enable attackers to bypass additional security layers, potentially leading to unauthorized access, data exfiltration, or further exploitation of the compromised account. Data_source:
-Google Workspace
search:`gws_reports_admin` command=UNENROLL_USER_FROM_STRONG_AUTH | stats count min(_time) as firstTime max(_time) as lastTime by user, command, actor.email, status, id.applicationName, event.name, vendor_account, action | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `gcp_multi_factor_authentication_disabled_filter`
how_to_implement:You must install the latest version of Splunk Add-on for Google Workspace from Splunkbase (https://splunkbase.splunk.com/app/5556) which allows Splunk administrators to collect Google Workspace event data in Splunk using Google Workspace APIs. Specifically, this analytic leverages the Admin log events. known_false_positives:Legitimate use case may require for users to disable MFA. Filter as needed. References: -https://support.google.com/cloudidentity/answer/2537800?hl=en -https://attack.mitre.org/tactics/TA0005/ -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:'$info_max_time$' tags: analytic_story: - 'GCP Account Takeover' asset_type:GCP confidence:90 impact:50 message:MFA disabled for User $user$ initiated by $actor.email$ mitre_attack_id: - 'T1586' - 'T1586.003' - 'T1556' - 'T1556.006' observable: name:'user' type:'User' - role: - 'Victim' name:'actor.email' type:'User' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'actor.email' - 'user' - 'command' - 'status' risk_score:45 security_domain:identity
