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Suspicious Login Activity Classified By Google — Sigma Rule

Sigma rule 38360161-76c4-4283-842e-efcf997dafc8. Suspicious Login Activity Classified By Google — Sigma Rule. Detects Google Workspace login activity that's classified as suspicious by Google.

Rule metadata and linked tags

experimentalmediumgcpgoogle_workspace.loginattack.initial-accessattack.privilege-escalationattack.persistenceattack.stealthattack.t1078.004

Author: Tom Kluter. Source status: experimental; severity: medium. Source dates: 2026-04-28 / not supplied.

{
  "product": "gcp",
  "service": "google_workspace.login"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 09ae5b63e473b90b113b90eae53411fae37f71fc70bb9d963dd64b0b8d1e6475

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Suspicious Login Activity Classified By Google
id: 38360161-76c4-4283-842e-efcf997dafc8
status: experimental
description: Detects Google Workspace login activity that's classified as suspicious by Google.
references:
    - https://cloud.google.com/logging/docs/audit/gsuite-audit-logging
    - https://cloud.google.com/logging/docs/audit/understanding-audit-logs
    - https://developers.google.com/workspace/admin/reports/v1/appendix/activity/login#suspicious_login
    - https://developers.google.com/workspace/admin/reports/v1/appendix/activity/login#suspicious_login_less_secure_app
    - https://developers.google.com/workspace/admin/reports/v1/appendix/activity/login#suspicious_programmatic_login
author: Tom Kluter
date: 2026-04-28
tags:
    - attack.initial-access
    - attack.privilege-escalation
    - attack.persistence
    - attack.stealth
    - attack.t1078.004
logsource:
    product: gcp
    service: google_workspace.login
detection:
    selection:
        protoPayload.Servicename: 'login.googleapis.com'
        protoPayload.metadata.event.eventName:
            - 'suspicious_login_less_secure_app'
            - 'suspicious_login'
            - 'suspicious_programmatic_login'
    condition: selection
falsepositives:
    - Legitimate logins
level: medium

Original YAML and metadata in JSON

False positives

  • Legitimate logins

Source references

Connected ecosystem references

Exact source-tagged techniques

Telemetry review

Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.

Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.