Friday, January 26, 2007

Creating Critical System Process in .NET

Yestreday, my home computer was infected by a worm - "Win32/Brontok.A". While cleaning it up I detected that I have TWO lsass.exe processes in the task manager. lsass.exe is a system process of the Microsoft Windows security mechanisms. The worm created lsass.exe in the My Documents folder, launched it and was happily operating on my machine.

And here's most interesting fact, when you try to kill lsass.exe process via task manager, you'll receive warning, like in the picture below.

I used Process Exloperer tool to kill that process and desinfect my computer.
However, it was interesting to see that Task Manager checks process name and not some special things about system process ( digital signature? ).

I created simple console application in C#, named it lsass.exe and voila - I have criticall system process :8-)