Exploring the history of computer viruses tends to make readers a bit paranoid, especially if they’ve been struck by one of these malicious programs in the past.
But if you’re curious about the dark side of computing you can explore the ghosts of viruses past, complete with awesome graphic addition, at the Computer Virus Catalog, “an illustrated guide to the worst viruses in computer history”.
There you can read about the LSD virus, a DOS based virus that "overwrites all the files in the current directory and then displays a druggy video effect", or the Madman virus, a DOS virus that infects .exe files- "Whenever you hit CTRL-ALT-DEL the virus displays an ASCII picture of an angry red-faced amigo. Hit your keyboard again and the virus displays the creepy message: 'Nothing can save you here, friend - you're in my world now!'_"
For some this site will be informative, but for those who practically live on their computers (like I do) this information makes for a downright terrifying read! *shivers*