The word “virus” and its association with computers was affixed by American computer scientist Frederick Cohen who used it to describe “a program that can ‘infect’ other programs by modifying them to include a possibly evolved copy of itself” way back in 1983. They come in all flavours, from problematic worms that spread like wildfire to backdoor entrances caused by trojan horse imposters.
Over the years there have been some very high-profile virus alerts, many of which caught mainstream media attention. In this article I will be exploring 5 of the very worst (best?) computer viruses ever to be compiled and unleashed on the web. Bug spray at the ready…
October 2001: Klez
Before 2001 and the Klez virus, all viruses that spread via email were sent from the infected recipient’s email address. Whilst this was still massively problematic as the web was adjusting to words like “trojan” and “worm”, Klez turned the heat up an extra notch.
Klez was in fact the first virus to be able to spoof email addresses, replacing the address in the “From” field with anyone else it pleased. This made avoiding detection difficult, and once a user became infected the infection was quickly passed on via email address books.
