Suspicious GCP Service Account Impersonation via GenerateAccessToken

ATT&CK techniques

Persistence → Lateral Movement

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1098.003Additional Cloud Roles
Priv Esc
- T1098.003Additional Cloud Roles
Defense Evasion
- T1550.001Application Access Token
Cred Access
Discovery
Lateral Movement
- T1550.001Application Access Token
Collection
C2
Exfiltration
Impact

What it detects

This rule detects use of the IAM Credentials GenerateAccessToken method, which mints short-lived access tokens for a service account through impersonation. Adversaries granted serviceAccountTokenCreator invoke this call, often via gcloud with impersonate-service-account, to act with the target service account permissions. It is important because impersonation lets an attacker operate under a more privileged identity while obscuring their originating principal.

Reporting behind it

Related detections9 linkedT1098.003 — drag to rearrange

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Malicious IAM Group Creation for SES Abuse by JavaGhost (via cloudtrail)

Malicious Administrator Policy Attachment for Privilege Escalation in AWS

Suspicious Azure Contributor Role Assignment to Identity

Suspicious Entra Sign-In With Axios Automation User-Agent via AiTM Token Replay (via azure)

Malicious Azure AD Token Abuse via Roadtx

Suspicious GCP Service Account Impersonation via GenerateAccessToken

Pivot detection · T1098.003 · 9 related

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

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