Creeper virus

1971

Computer pioneer John von Neumann’s posthumous work Theory of Self-Reproducing Automata, was published in 1966. Five years later, the first known computer virus, called Creeper, was written by Bob Thomas. Written in PDP-10 assembly language, Creeper could reproduce itself and move from computer to computer across the nascent ARPANET.

Creeper did no harm to the systems it infected - Thomas developed it as a proof of concept, and its only effect was that it caused connected teletype machines to print a message that said “I’M THE CREEPER: CATCH ME IF YOU CAN.”