Nvirundll.exe is a Backdoor W32.Spybot.NPS. Nvirundll.exe spreads via open network shares . Nvirundll.exe tries to terminate antiviral programs installed on a user computer. Nvirundll.exe monitors user Internet activity and private information. It sends stolen data to a hacker site. Related files: %System%\nvirundll.exe Adds the value: "nvirundll" = "nvirundll.exe" to the Windows startup registry keys. More info: http://securityresponse.symantec.com/avc... Removal: Kill nvirundll.exe process and remove nvirundll.exe from Windows startup using antivirus (also check How To Remove section)Startup Optimizer.