The 'GCP DNS Zone Modified or Deleted' rule is designed to detect critical changes to Google Cloud Platform (GCP) DNS zones, including modifications, deletions, or updates. Given the potential for high-impact activities, such as downtimes or outages, this rule ensures that any significant adjustments are recorded and flagged for review. It targets operations that include the deletion of managed zones and the modification of DNS configurations. The rule tracks the actions of authorized users through GCP audit logs, capturing details such as the principal email of the user performing the action and the specific method invoked (delete or update). Furthermore, it provides insights into the expected log results to confirm whether the alerts are triggered correctly. Detection is based on operations related to the management of DNS zones to maintain optimal DNS functionality and security.