When was the first computer virus created?

Engineer Bob Thomas at BBN wrote Creeper in 1971 as an experiment on ARPANET, the forerunner of the internet, and it displayed the message I’M THE CREEPER: CATCH ME IF YOU CAN. A follow-up program called Reaper was written to hunt it down, arguably the first antivirus. In 1982 a 15-year-old student, Rich Skrenta, created Elk Cloner, which spread between Apple II computers on floppy disks and displayed a short poem. The term computer virus was used by researcher Fred Cohen in 1983, and in 1986 Brain became the first virus for IBM-compatible PCs. Later outbreaks such as the ILOVEYOU worm in 2000 infected millions of computers worldwide.