Msnl.exe is a mass-mailing worm W32.Mytob.IK@mm. Msnl.exe opens a back door on TCP port 8881. Msnl.exe tries to terminate antiviral programs installed on a user computer. Related files: %System%\msnl.exe Adds the value: "WINDOWS SYSTEM" = "msnl.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill msnl.exe process and remove msnl.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.