huntrule

GCP Google Workspace Suspicious Login Events (Google Classified)

Alerts on Google Workspace login audit events classified by Google as suspicious, including less secure app and programmatic login types.

FreeReviewedSigma · Medium · v4
Product
gcp
Service
google_workspace.login
Author
Tom Kluter (SigmaHQ), DRL 1.1
Published
2026-04-28
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access → Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags Google Workspace login audit events where Google has classified the login as suspicious. Such activity can indicate attacker attempts to access accounts using less secure authentication methods or automated/programmatic login patterns. It relies on GCP audit log telemetry from login.googleapis.com and matches specific eventName values in protoPayload.metadata.event.eventName.

Reporting behind it

Related detections9 linkedT1078.004 — drag to rearrange
Suspicious Google Cloud Function Create or Update Triggering Build
Possible Credential Stuffing Blocked by Conditional Access in Microsoft 365
Suspicious SES Account Sending Enablement and Identity Verification via CloudTrail
Possible Stolen AWS Credential Validation via STS GetCallerIdentity
Suspicious AWS Federated Console Login From Programmatic Credentials
Suspicious M365 Legacy Authentication via BAV2ROPC Client via m365
Suspicious STS AssumeRole With Exfil Session Name via CloudTrail (via cloudtrail)
Suspicious AWS Console Login Without MFA
Suspicious Cloud Sign-In From an Anonymizer or High-Risk Session (via signinlogs)
GCP Google Workspace Suspicious Login Events (Google Classified)
Pivot detection · T1078.004 · 9 related

Changelog

v4
  1. v4
    Candidate ingested via manual entry.2026-07-31
  2. v3
    Candidate ingested via manual entry.2026-07-31
  3. v2
    Candidate ingested via manual entry.2026-07-31
  4. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.