mtask.exe is a Trojan.Mkmoose-B. mtask.exe opens a back door. Related files: %System%\msmgs.exe %System%\mtask.exe More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill mtask.exe process and remove mtask.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.