T1113 Screen Capture – DcRAT / Millenium RAT image file staging by non-UI processes
This rule detects screen capture activities associated with DcRAT, Millenium RAT, and Operation DragonReturn. It identifies the creation of specific staging files (e.g., debug.txt, background.jpg) at sensitive paths and monitors for non-standard or masquerading processes (such as svchost.exe running outside System32) that create image files in user-writable or temporary directories. The rule uses tiered logic, assigning a higher risk score to known IOC patterns and periodic capture behavior.
Microsoft Sentinel (KQL)
