This detection rule is designed to identify unauthorized modifications to the configuration of storage buckets in Google Cloud Platform (GCP). Adversaries may attempt to weaken security controls by changing the settings of storage buckets, which can lead to unauthorized access or data exfiltration. The rule triggers when audit logs show a successful change to a storage bucket's settings, specifically monitoring the event action 'storage.buckets.update'. Security teams can investigate to ensure that such modifications are legitimate and do not indicate malicious behavior. The investigation steps recommend reviewing audit logs, confirming the user or service account involved, and assessing permissions and roles to detect any unauthorized activities. It is essential to identify false positives, such as routine administrative actions or automated scripts, and ensure they do not trigger unnecessary alerts. Response measures involve revoking unauthorized access, reverting configuration changes, and notifying relevant teams for coordinated response efforts. The rule is applicable for environments compliant with the GCP Fleet integration or Filebeat module, aiding in the detection of potential defense evasion tactics used by adversaries.