Viruses, Spyware and Worms

An excellent series on Viruses, Spyware and Worms:

Imagine you are a fairly technical person. You are pretty smart about what software you install. Unfortunately, someone on your LAN gets a virus that exploits a vulnerability of your computer’s operating system that your OS vendor was not aware of. The virus installs a ‘root kit’, a type of virus that is not detectable once it is installed in your kernel. If the virus is sophisticated, you would not even notice. Not even your “up to date” virus checker notices anything. Your computer can now be used by someone else, for almost whatever else.