These are the 3 Worst Computer Viruses in History

Computer viruses can cause significant harm to your devises. Hackers, spammers and those plotting cyberattacks date back to the start of computing. Over time, several viruses have been particularly damaging. Here are the three worst computer viruses of all time:

History’s Worst Computer Viruses


Code Red is an insidious worm that should strike fear in all users because it can infect computers through a basic internet connection. No human action, like opening an attachment or visiting a website, was required. Code Red emerged in mid-2001. It infected devices by scanning networks for a host.

Once identified, it inundated the computer with random data requests to overwhelm the system to the extent that it began to overwrite its own memory. Code Red invaded countless machines, including computers at the White House.


ZeuS is technically a Trojan-horse, rather than a virus, but it makes our list due to the damage it caused. Some viruses insert lines from sitcoms into documents or share photos of celebrities with mailing lists unbeknownst to users. ZeuS, however, performs criminal acts of keylogging and form grabbing. It infected the computers of personal users as well as global corporations.