TOP FIVE COMPUTER VIRUSES

Top 5 Computer Viruses


They can wipe out your hard drive. They can crash servers and send shock waves around the cyber world. And they can embarrass you. Here are the biggest computer viruses in cyber history, so far:

1. Brain (1986)

This is the one that started it all. Created by two Pakistani brothers, the Brain virus is widely considered to be the first PC computer virus ever. It wasn't particularly virulent. It was a boot sector infector, and was accompanied by the creators' names and phone numbers. The brothers swore the intention was not malicious, but the genie was out of the bottle; the Brain virus became the model for numerous viruses and other malware for years to come.

2. Melissa (1999)

The Melissa virus was one of the first viruses to be spread via e-mail, crashing corporate networks by taking advantage of the increasingly popular Microsoft Outlook mail client. The virus was spread by an infected attachment to the email, and automatically sent itself to the first 50 names in the user's address book, making it the first virus to move from one computer to another on its own. The amount of email passing through servers quickly increased exponentially, forcing shutdowns and business stoppages. The Melissa virus was also noteworthy because its creator was caught and sent to prison.

3. ILOVEYOU (2000)

This is the virus that made us all afraid to open attachments. ILOVEYOU was one of the first to trick users into opening the file that actually activated the virus. The ILOVEYOU worm masqueraded as a love letter sent via e-mail, but instead was a computer script that sent copies of itself to users' Microsoft Outlook address book entries, overwrote and deleted computer files, modified Internet Explorer pages, and even interfered with Registry keys. It caused billions of dollars worth of damages, and is still considered one of the worst worms ever.

4. Klez (2001)

Yet another e-mail virus, Klez makes the list because it pioneered "spoofing," the trick of making it seem as if an email comes from someone other than the actual sender. Thanks to Klez, you can't trust that an email that appears to be from your mom is actually from your mom; a spammer may have "spoofed" the From field. Klez spreads itself using open networks and e-mail. Unlike other viruses, it doesn’t require Microsoft Outlook to spread itself – and while it isn't a particularly malicious virus, it can corrupt files and interfere with some software. Klez is also notoriously hard to exterminate, and versions of it continue to turn up fairly regularly.

5. Benjamin (2002)

Benjamin is significant in virus history because it’s the first that spread itself via a file-sharing program, in this case, Kazaa. It tricked users into thinking they were downloading media files. Instead, they downloaded the Benjamin virus. Benjamin created its own folder on the user's computer, filled the folder with replicated versions of itself, and then made itself available for sharing to other Kazaa users. Benjamin's primary effects were to overload a user's hard drive and eventually to slow down networks, but aside from that it wasn’t particularly malevolent.

BONUS: THE ANNA KOURNIKOVA VIRUS (2001)

The Anna Kournikova virus didn't really cause any major harm or data loss, but it did cause embarrassment. It was spread by users clicking on an attachment that promised to be a hot picture of the tennis star. Naturally, opening the attachment unleashed the virus, which sent itself to all of the contacts in the user's Microsoft Outlook address book. Server overload caused business stoppages, and numerous users were forced to admit that they found the promise of an Anna Kournikova image impossible to resist.

To learn more about malware, viruses, spyware and Trojan horses, watch VideoJug's series of informative videos with computer security expert "Hacker X."