The best way to protect yourself against virus and worm infection is to regularly scan your computer with an up-to-date Anti-Virus software program. Trojans exploit open ports on your computer (the most common ports used are ports 80, 21, and 25) and the best protection is to have a properly installed firewall on your machine. To protect your computer from Spyware programs, which perform a variety of malicious acts, you should install one or more Spyware removal programs on your computer and run them regularly.