Anomalous number of Google Cloud Storage Buckets Accessed

Goal

Detect when a Google Cloud identity accesses a number of Google Cloud Storage buckets that they do not usually access.

Strategy

Monitor Google Cloud Audit logs to identify when a Google Cloud identity makes an anomalous number of storage.buckets.get calls to a unique number of Google Cloud Storage buckets (bucket_name).

Triage and response

  1. Determine if the user: {{@usr.id}} should be accessing the storage buckets.
    • Here is a list of buckets that were accessed (up to 10): {{bucket_name}}
  2. If the action is legitimate, consider including the user in a suppression list. See this article on Best practices for creating detection rules with Datadog Cloud SIEM for more information.
  3. Otherwise, use the Cloud SIEM - User Investigation dashboard to see if the User: {{@usr.id}} has taken other actions.
  4. If the results of the triage indicate that an attacker has taken the action, begin your company’s incident response process and investigate.