The Most Widespread Viruses
The costliest computer viruses in history were also some of the most widespread. While the viruses below didn’t cause as much damage, they rivaled Mydoom, Sobig, and Klez in terms of how quickly and vastly they proliferated.
How widespread: Affected 10 million computers
For romantics such as ourselves, catching the love bug is a good thing. But for computer owners in 2000, it wasn’t. The Love Bug virus, otherwise known as the ILOVEYOU virus, infected over 10 percent of the world’s computers. The secret to its success? A self-replicating virus executed with a pinch of social engineering.
The ILOVEYOU virus spread through (surprise, surprise!) emails. The subject line read “ILOVEYOU” with an attached file titled “LOVE-LETTER-FOR-YOU.txt.vbs.” Anyone intrigued enough to find out who sent them the love letter quickly found out that it wasn’t from an admirer. Once a computer was infected, the virus scraped it for email contacts and started spreading itself. And that’s how a simple malicious email infected over 10 million computers worldwide.
How widespread: Affected 88 percent of all Fortune 500 companies in 2007
Zeus seized control over computers belonging to 88 percent of all Fortune 500 companies in 2007, and that’s just the start of it. Zeus is a botnet trojan virus. It spread primarily through spam emails (of course!) and drive-by downloads, which is when it piggybacked onto compromised files and executed the infection when someone downloaded the seemingly legitimate file. At one point, it was found in over 76,000 computers worldwide.
Zeus targeted financial institutions in particular, and once a computer was infected, it became a part of a “botnet.” All infected bots gave the “bot master” — a puppeteer of sorts that can simultaneously control all computers in the botnet — backdoor access. And with thousands of computers at its disposal, the bot master could (and did) execute mass attacks. Crimes like DDoS attacks, mass hacking, data breaches, and online banking theft have been linked to the Zeus virus since 2007.
How widespread: Affected 200,000 systems, mostly businesses
WannaCryptor, or WannaCry for short, is one of the most devastating and ruthless viruses in recent memory. It’s actually ransomware. Once it infects a computer, it encrypts its files to lock out the owner and then demands a ransom in Bitcoin. If one fails to meet the ransom demands, they’re locked out of their files forever.
WannaCry wasn’t sneaky or clever, but somehow it picked the right targets to cause maximum damage. At one point, Renault, the French car manufacturer, had to close its European manufacturing plants to contain the spread of the virus. Hospitals, airline networks, financial institutions, and even FedEx had fallen victim as well.
Can Antivirus Software Stop These Viruses?
We know, we know, that’s a silly question. It’s like asking if Batman, the protector of Gotham, can beat the Joker. Of course he can, and of course, antivirus software can stop even the most devastating viruses in history. Cybersecurity has come a long way since the turn of the millennium, and the viruses released then, no matter how devastating, can easily be stopped today.
But then, the same can be said about the state of cybersecurity around the time those viruses proliferated. Cybersecurity in the early 2000s was a lot better than cybersecurity in the 1980s and ’90s. Still, the viruses we just discussed managed to wreak havoc. Who’s to say that there won’t be a more devastating virus that can evade the detection of current antivirus technology?
That brings us to our next and final point: What can you do to protect yourself if and when the next big computer virus hits?