BihUpdate.exe is a mass-mailing worm W32.AJM.Worm. BihUpdate.exe spreads by e-mail and via open network shares. Related files: %System%\User32Rem.exe %System%\UserGDL.exe %System%\BihUpdate.exe %System%\SysRtw32.exe %System%\Win32Dll.exe %System%\MsCrt32.exe %System%\Temp32.exe More info: http://securityresponse.symantec.com/avc... Removal: Kill BihUpdate.exe process and remove BihUpdate.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.