princesscheroke the reason NAV or AVG do not detect exim.exe as a virus/trojan is because it is not. its just an smtp server placed there for illegal purposes. AV programs do not recognize ligitimate programs as viruses. so netcat which is mearly a network tool will also go undetected even in listening mode as would, ftp, vnc or radmin to name a few. these services can be hidden from the task manager (and the systray) very easily. there are back doors that respond to udp that do not show as listening ports. be very careful. mearly deleating exim may just give you a false sense of security.