The detection rule 'Azure Active Directory Hybrid Health AD FS Service Delete' is designed to track and alert on unauthorized deletions of Azure Active Directory Hybrid health AD FS service instances in a tenant environment. This rule relies on azureactivity logs categorized under 'Administrative' events. A potential threat actor could exploit this functionality by creating a fraudulent AD Health ADFS service, possibly mimicking a legitimate server and falsifying AD FS signing logs. Once the malicious service is no longer needed, they might send HTTP requests to delete the service, raising security concerns. The detection is achieved by monitoring for specific attributes within the activity logs, particularly if instances related to 'Microsoft.ADHybridHealthService' are deleted. This rule aims to catch such suspicious deletions before any damage is inflicted. The false positive scenarios include legitimate service deletions that occur within the organization that are not tied to malicious intent.