This detection rule identifies the use of the PowerShell command `Set-MpPreference`, which modifies or disables Windows Defender settings. It specifically targets situations where an unauthorized user might disable antivirus protections, a common tactic employed by threat actors to facilitate malicious activities on Windows systems. The rule uses Elastic Query Language (EQL) to filter PowerShell process execution events where the process name is `powershell.exe`, `pwsh.exe`, or similar, and where the command arguments indicate disabling features of Windows Defender. Analysts are provided with investigative guidelines, including the need to assess the legitimacy of the activity against planned configurations, validate user accounts, and analyze execution chains to identify potential threats. False positive considerations are also addressed, highlighting scenarios where administrators may intentionally disable Defender features for legitimate purposes, thus allowing for alert dismissal. The rule contributes to a broader effort to monitor and respond to defense evasion tactics in the Windows environment.