The Creeper virus is the first computer virus ever developed. Bob Thomas created it in 1971 as an experimental self-duplication program. … It messed up connected teletype computer screens, causing them to display the message, “I’m the creeper, catch me if you can!”
The Elk Cloner virus was the first virus in history that affected a machine during its boot-up process. Today, the popular term for such viruses is ‘boot sector virus’.
The virus affected the boot sector of infected Apple machines by attaching itself to an innocent looking game. Every 50th time that the machine would boot up, a blank screen and a poem would flash on the screen.