The detection rule "Cisco Duo Bulk Policy Deletion" monitors for instances where a Duo administrator performs a bulk deletion of more than three security policies in a single action. This rule is critical for a Security Operations Center (SOC) as mass deletions may signal potential security threats, such as malicious actions by rogue administrators or attackers attempting to disable critical security measures. The rule works by analyzing Duo activity logs for occurrences of the 'policy_bulk_delete' action, identifying which policies were deleted, and counting these occurrences. If more than three policies are deleted in one action, the rule flags this event for further investigation. The analytic leverages Splunk to process data and provide insights into changes made to security policies. Detection of this behavior is important to maintain security posture and ensure unauthorized changes are promptly addressed.