These are the 3 Worst Computer Viruses in History

3 Worst Computer Viruses in History

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

1. Code Red

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.

2. ZeuS

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.

After stealing login information, criminals had access to everything from social media to banking accounts. Around $100 million dollars was stolen by a large ring of cyber criminals from around the world. Most of the damage occurred in 2009, with the creator of ZeuS triumphantly declaring his retirement from cybercrime in 2010. Many people worry that the creator and/or his large ring of counterparts could strike again.


The ILOVEYOU virus is often considered the single most devastating computer virus of all time. Aptly named, the virus harnessed people’s curiosity about a supposed love confession in an email attachment. The attachment posed as a text file but was actually a script that would replicate, send itself to everyone in the user’s contact list, and overwrite files until the computer would no longer boot. It was so heavily opened by email users that the virus spread at an alarming rate. The virus damaged computers and various systems in every corner of the world. With an estimated cost of $10 billion dollars, ILOVEYOU infected approximately 10% of the world’s connected computers. Government sectors responded by going offline but for many, it was too late.

Unfortunately, many of us have experienced the havoc that a computer virus can wreak. The damage can range from the frustration of a sluggish computer to complete data loss. It’s important to keep antivirus software up-to-date and a consistent data backup plan in place. Even the most diligent defense strategies can’t always fend off the damage caused by viruses or malware.

If you’ve been struck by a virus and need help to recover your hard drive, submit an online help form today.