This detection rule identifies when Windows Defender services are disabled by monitoring specific registry modifications. It particularly tracks changes to registry keys associated with Defender, specifically looking for instances where the 'Start' value is altered to '0x00000004', indicating that these services have been set to disable. Such behavior is often an indicator of malicious activity, as attackers may aim to eliminate or reduce security measures in order to execute further unauthorized actions on an endpoint undetected. By using Sysmon event logs, the rule leverages critical registry event data to identify unauthorized service modifications that could signify an ongoing breach or persistence mechanism employed by adversaries.