GCP Successful Single-Factor Authentication

name: GCP Successful Single-Factor Authentication
id: 40e17d88-87da-414e-b253-8dc1e4f9555b
version: 11
date: '2026-03-10'
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
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: $info_max_time$
rba:
    message: Successful authentication for user $user$ without MFA
    risk_objects:
        - field: user
          type: user
          score: 50
    threat_objects:
        - field: src_ip
          type: ip_address
tags:
    analytic_story:
        - GCP Account Takeover
        - Scattered Lapsus$ Hunters
    asset_type: Google Cloud Platform tenant
    mitre_attack_id:
        - T1078.004
        - T1586.003
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: identity
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078.004/gcp_single_factor_auth/gws_login.log
          source: gws:reports:login
          sourcetype: gws:reports:login