Fdd.exe is a mass-mailing worm W32.Mytob-FO. Fdd.exe opens a back door. Fdd.exe tries to terminate antiviral programs installed on a user computer. Related files: %System%\Fdd.exe More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill Fdd.exe process and remove Fdd.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.