The 'Windows AD Suspicious GPO Modification' analytic focuses on identifying potentially harmful changes to Group Policy Objects (GPOs) within a Windows Active Directory environment. It operates by monitoring event logs related to GPO modifications, specifically looking for Event ID 5145 (which records file share access) and Event ID 5136 (which records changes to GPOs). The rule aims to detect suspicious activities that suggest unauthorized edits to GPOs that could enable persistence or remote code execution. Notably, this analytic is sensitive to the absence of Event ID 5136 logs, indicating manual edits or missing logging, potentially performed with tools like PowerView. Detection logic employs a series of conditions within the search query to filter the relevant events and extract insights relating to the nature of the modifications, users involved, and the specific GPOs impacted. The implementation requires proper SACL configurations to capture the necessary events, and consideration is given to tuning out noise from non-relevant events.