What are some interesting facts about computer viruses?

A program named "Rother J" was the first computer virus to come into sight "in the wild" - that is, outside the single computer or lab where it was created. Created in 1981 by Richard Skrenta, it attached itself to the Apple DOS 3.3 operating system and spread via floppy disk. This virus was created as a practical joke when Richard Skrenta was still in high school. It was injected in a game on a floppy disk. On its 50th use the Elk Cloner virus would be activated, infecting the computer and displaying a short poem beginning "Elk Cloner: The program with a personality."