PowerShell Desktop Wallpaper Modification

SigmaHQ Detections@sigmaHQ

•updated Aug 12, 2024•0•17

This rule detects attempts to change the desktop wallpaper using PowerShell. It specifically looks for PowerShell script block text that either modifies the 'WallPaper' property within the 'HKEY_CURRENT_USER\Control Panel\Desktop\' registry key or calls the 'SystemParametersInfo' function with specific parameters (20, 0, *, 3), which is a Windows API call used to set the desktop wallpaper. This activity is indicative of an adversary attempting to deface a system.