Name:GCP Successful Single-Factor Authentication id:40e17d88-87da-414e-b253-8dc1e4f9555b version:4 date:2024-09-30 author:Bhavin Patel, Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic identifies a successful single-factor authentication event against Google Cloud Platform (GCP) for an account without Multi-Factor Authentication (MFA) enabled. It uses Google Workspace login event data to detect instances where MFA is not utilized. This activity is significant as it may indicate a misconfiguration, policy violation, or potential account takeover attempt. If confirmed malicious, an attacker could gain unauthorized access to GCP resources, potentially leading to data breaches, service disruptions, or further exploitation within the cloud environment. Data_source:
-Google Workspace login_success
search:`gws_reports_login` event.name=login_success NOT `gws_login_mfa_methods` | stats count min(_time) as firstTime max(_time) as lastTime by user, src_ip, login_challenge_method, app, event.name, vendor_account, action |`security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `gcp_successful_single_factor_authentication_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 User log events. known_false_positives:Although not recommended, certain users may be required without multi-factor authentication. Filter as needed References: -https://attack.mitre.org/techniques/T1078/004/ -https://support.google.com/a/answer/175197?hl=en -https://www.forbes.com/sites/daveywinder/2020/07/08/new-dark-web-audit-reveals-15-billion-stolen-logins-from-100000-breaches-passwords-hackers-cybercrime/?sh=69927b2a180f 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:Google Cloud Platform tenant confidence:90 impact:50 message:Successful authentication for user $user$ without MFA mitre_attack_id: - 'T1586' - 'T1586.003' - 'T1078' - 'T1078.004' observable: name:'user' type:'User' - role: - 'Victim' name:'src_ip' type:'IP Address' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'event.name' - 'event.parameters{}.multiValue{}' - 'user' - 'src_ip' - 'login_challenge_method' risk_score:45 security_domain:identity
