arpo412.exe is a worm W32.PPdoor-R. arpo412.exe opens a back door. arpo412.exe spreads via open network shares. Related files: %System%\arpo412.exe %System%\mqadonfg.dll %System%\winrpmsg.dll %System%\wndfxyfi.dll %System%\hgakheg.dll %System%\vjoytl32.dll More info: http://www.sophos.com/virusinfo/analyses... Removal: Kill arpo412.exe process and remove arpo412.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.