Privilege Escalation: Anomalous Service Account Impersonator for Data Access

This document describes a threat finding type in Security Command Center. Threat findings are generated by threat detectors when they detect a potential threat in your cloud resources. For a full list of available threat findings, see Threat findings index.

Overview

Anomalous Service Account Impersonator is detected by examining the Data Access Audit Logs to see if any anomaly occurred in a service account impersonation request.

How to respond

To respond to this finding, do the following:

Step 1: Review finding details

  1. Open the Privilege Escalation: Anomalous Service Account Impersonator for Data Access finding, as directed in Reviewing findings.

  2. In the finding details, on the Summary tab, note the values of following fields.

    Under What was detected:

    • Principal email: the final service account in the impersonation request that was used to access Google Cloud
    • Service name: the API name of the Google Cloud service involved in the impersonation request
    • Method name: the method that was called
    • Service account delegation information: details of service accounts in the delegation chain, the principal at the bottom of the list is the caller of the impersonation request

Step 2: Research attack and response methods

  1. Contact the owner of the service account in the Principal email field. Confirm whether the legitimate owner conducted the action.
  2. Investigate the principals in the delegation chain to verify whether the request is abnormal and if any account has been compromised.
  3. Contact the owner of the impersonation caller in the Service account delegation info list. Confirm whether the legitimate owner conducted the action.

Step 3: Implement your response

The following response plan might be appropriate for this finding, but might also impact operations. Carefully evaluate the information you gather in your investigation to determine the best way to resolve findings.

  • Contact the owner of the project where the action was taken.
  • Consider deleting the potentially compromised service account and rotate and delete all service account access keys for the potentially compromised project. After deletion, resources that use the service account for authentication lose access. Before proceeding, your security team should identify all impacted resources and work with resource owners to ensure business continuity.
  • Work with your security team to identify unfamiliar resources, including Compute Engine instances, snapshots, service accounts, and IAM users. Delete resources not created with authorized accounts.
  • Respond to any notifications from Google Cloud Support.
  • To limit who can create service accounts, use the Organization Policy Service.
  • To identify and fix overly permissive roles, use IAM Recommender.

What's next