The first Creeper network virus appeared in the early 70s on the Arpanet military computer network, which was the prototype of the Internet. The program was able to independently access the network through a modem and save its copy on a remote machine. On infected systems, the virus detected itself with the message: I'M THE CREEPER: CATCH ME IF YOU CAN. In general, the virus was harmless, but it made the staff nervous.

To remove the annoying, but, in general, harmless virus, the unknown created the Reaper program. In fact, it was also a virus that performed some of the functions characteristic of an antivirus.The Reaper spread via network and in case of the detection of Creeper virus, destroyed it.