mstf.exe is a Trojan W32.Sdbot-AJV . mstf.exe opens a back door on IRC channels. mstf.exe spreads via open network shares. Related files: %System%\mstf.exe More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill mstf.exe process and remove mstf.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.