The Most Badass Computer Viruses

Why do hackers make viruses? There are a lot of reasons, but many malware masterminds just want to leave their mark on the world. Here are eleven examples of seriously intense viral attacks.

Melissa

As email began to become the preferred method of business communication, it became only natural for virus makers to start treating it as a disease vector. One of the first worms to get major attention was the Melissa virus, created in 1999 by David L. Smith and named after a stripper he had a crush on. Sent through an email, it was built on a simple Microsoft Word macro - if you opened the attached document, it would automatically replicate itself and re-send to the top 50 names in your address book. Melissa crashed multiple networks before it was contained, but it was only the beginning.

Pikachu

As more and more people started using email in their daily life, it's not surprising that virus makers are targeting kids with their work as well. The 2007 Pikachu worm is widely regarded to be the first piece of malware that focused on the pre-teen set. An email containing an image of the electric mouse Pokemon and some amazing Engrish reading "Between millions of people around the world I found you. Don't forget to remember this day every time MY FRIEND." led to a mass email to everybody in your address book as well as the addition of instructions to your autoexec.bat file that would wipe your hard drive on next boot.

Michaelangelo

One of the most devastating aspects of viruses is how they can lay dormant in your computer waiting for further instructions. The first virus to really create a worldwide panic was dubbed Michelangelo after its date of activation - on March 6th, the famous painter's birthday, this malicious bit of code would roar into action and delete the first 100 sectors of your hard drive, rendering your machine inoperative. Things got really crazy when it was discovered that some hardware manufacturers including Intel had shipped products that were accidentally pre-infected with the virus, and the media actually advised people to not turn their computers on at all on the 6th until a cure could be found.

Nimda

One of the most damaging worms we've ever seen was Nimda, which was released on September 18, 2001. Its timing led many to believe that it represented a cyber-security attack after the events of September 11th, but that theory ended up not being true. The worm ushered in a new era of propagation because it didn't rely on just one vector to be effective. Sure, you could screw up your computer by opening an email attachment like a dummy, but you could also get it from compromised websites, from network shares, and even from backdoors left open by other worms.

Morris

By the time the Morris worm was done doing damage, it had become the first piece of malicious software to result in a court conviction. Cornell University student Robert Tappan Morris created his self-replicating program as part of an experiment to judge the number of computers connected to the Internet. Unfortunately, a flaw in his code resulted in the virus replicating itself excessively, bringing down multiple systems and causing hundreds of thousands of dollars in damages. Morris was apologetic and after paying $10,000 in fines and doing community service accepted a professorship at MIT.

Storm

Getting onto your computer and replicating is only half of the job when it comes to viruses. The other part is exploiting that newfound access. One of the most terrifying worms in recent memory was Storm - this backdoor trojan was first spotted in 2007 and spread like crazy through networks in Europe and the United States. Once infected, your computer would be slaved to the Storm botnet, a conglomeration of computers reportedly 160,000 strong that performs illegal online activities without the user ever knowing about it.

Sasser

As we become more dependent on our computer systems, worms and viruses can cause more and more real damage. The Sasser worm, so dubbed because it spread through a vulnerability in Microsoft's Security Authority Subsystem Service, hit the world in 2004 and rapidly started messing things up. Created by German srudent Sven Jaschan and released on his eighteenth birthday, it caused effects including cancelling Delta transatlantic flights, disabling the X-ray department in a major hospital and forcing several major European financial companies to close down until their systems could be purged.

Vundo

As new security companies began to roll out products to battle the ever-proliferating spread of viruses, cyber criminals got creative. Vundo, also known as Virtumonde, is one of the nastiest trojans out there right now. Either spreading through e-mail attachments or through Java vulnerabilities in compromised websites, this nasty bit of business essentially hijacks your system with a fake antivirus warning, slowing your machine to a crawl and redirecting you to an online retailer where you can buy a program that will allegedely clean your system out. Let's just say you don't want to give your credit card number to these people.

MyDoom

Viruses and worms are judged by two major factors - how fast they spread and how much damage they do. 2004's MyDoom infestation currently holds the record for the first, as on the first day of its release in January it had replicated so many times that worldwide internet performance was slowed by 10% and doubled the load page time for most websites. This baby traveled fast, and by the time analysts got into it and discovered that it was set to launch a DDOS attack on February 1st panic was widespread. By the time that date rolled around, there were a million infected computers participating, the largest number up to that point.

Koobface

As social networking becomes a bigger and bigger part of our online lives, it's no surprise that malicious software engineers are developing ways to target us there. Koobface is one of the nastiest, hitting users of Facebook as well as MySpace, Twitter, Bebo, even Friendster. Infected computers send Facebook messages to everybody on their list with innocuous names like "You look great in this movie." That redirects users to an infected website that prompts you to update your Flash player. That "update" is actually the virus, which then spreads through your network.

ILOVEYOU

And we end with one of the most damaging viruses in computer history. ILOVEYOU was first spotted in 2000 spreading through email, with an attachment named "Love-letter-for-you." This early in the game, people weren't on their guard, and so the infection spread like wildfire, originating in the Philippines and blazing through Europe and the United States in just days, overwriting a wide variety of files - most commonly documents and media - and re-sending itself through Microsoft Outlook. Approximately $5.5 billion dollars in damages have been ascribed to this one humble worm, which even inspired a 2010 movie Subject: I Love You starring Dean Cain.