First computer virus turns 20

Two decades ago, Brain, the first boot sector virus that infected personal computers via the floppy disk, was detected. While Brain itself was relatively harmless, it marked the genesis of the world of computer viruses.

This year marks the 20th year of the existence of viruses after Brain was detected on January 19, 1986.

Boot sector viruses, now long extinct along with the floppy disk, held a relatively long reign from 1986 to 1995. Since transmission was via disk from computer to computer, infection would only reach a significant level months or even years after its release.

This changed in 1995 with the development of macro viruses, which exploited vulnerabilities in the early Windows operating systems. For four years, macro viruses reigned over the IT world and propagation times shrank to around a month from the moment the virus was found to when it became a global problem.