The first computer virus is attributed to a program called "Creeper," developed by Bob Thomas in the early 1970s. Creeper was designed to self-replicate and spread across computers in the ARPANET, displaying the message: "I'm the creeper, catch me if you can!" Later, the Reaper program was created to remove Creeper, marking the beginnings of the cat-and-mouse game between malware developers and cybersecurity experts. This historical development paved the way for the evolution of more sophisticated viruses and cybersecurity measures in modern computing.