crohrs: 100% sure, as TruStarwarrior has also confirmed.

VTOLfreak: mdm.exe may be the Microsoft "Machine Debug Manager", which is part of the Microsoft Script Debugger for Internet Explorer, or a similar type of Microsoft debugger. Usually, it's only there if you installed the IE script debugger.

As long as mdm.exe is being run from c:\windows\system\mdm.exe and the properties of the file show a bunch of microsoft copyrights and info, you're probably alright.

Zildy