This detection rule monitors for registry modifications that indicate the establishment of a screensaver after the execution of a malicious .scr file via Rundll32. It specifically targets changes to the 'SCRNSAVE.EXE' path in the Windows registry, which is a common technique used by attackers to execute scripts and evade defenses. The rule integrates conditions that check for the activity of 'rundll32.exe' and scrutinizes the details of the targeted object 'Control Panel\Desktop\SCRNSAVE.EXE' to verify that it is associated with screensaver files. If the execution of 'rundll32.exe' and the subsequent registry modification occur without any of the specified filters (i.e., legitimate system paths), the detection rule will trigger an alert. False positives may arise from legitimate use cases where users intentionally set screensavers, thereby requiring careful investigation when alerts are generated to differentiate between legitimate and malicious activities.