Dcomuser.exe is a mass-mailing worm W32.Mytob.EO@mm. Dcomuser.exe tries to terminate antiviral programs installed on a user computer. Dcomuser.exe opens a back door on TCP port 6667. Related files: %System%\dcomuser.exe Adds the value: "WINDOWS SYSTEM" = "dcomuser.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill dcomuser.exe process and remove dcomuser.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.