Suspicious Screensaver Registry Modification by Reg.exe

SigmaHQ Detections@sigmaHQ

•updated Oct 23, 2025•0•19

This rule detects suspicious modifications to screensaver settings in the Windows Registry using `reg.exe`. Adversaries may manipulate these settings to establish persistence by executing malicious content when a user is inactive. Specifically, it looks for `reg.exe` commands that modify the `ScreenSaveActive`, `ScreenSaveTimeout`, `ScreenSaverIsSecure`, or `SCRNSAVE.EXE` registry values within `HKEY_CURRENT_USER\Control Panel\Desktop` or `HKCU\Control Panel\Desktop` with the `/f` (force) flag.