The worst computer viruses of all time

We've heard the term, 'computer virus' over 20 years. When I bought my first 80286 AT desktop on 1991, definitely Michelangelo, Jerusalem and Dark Avenger viruses were notorious and they were critial to data in PC. In that time, it was general copying games and utility programs among individuals then and those facilitated spread of computer viruses.

In other hands, in 2005, I downloaded some file from P2P program and one file contained very critical computer virus, which was identified as Win-Trojan/KillFiles.606208 later.

When I executed the file, drive C: was almost vanished. 30Gb of data was gone and only 320Mb of data remained. I tried to recover data by data recovery programs and ask for assistances to data restoration service company but they had never seen such a completely spoiled drive C: and data were forever gone. I've retained the file till now for someday, you should be careful not to stimulate my nerves as I have the powerful virus!! lol (Practically every PC vaccine is able to scan this virus now and even I cannot download it from my email service as the website automatically scans the files when the users try to download attached files.

Well, I spent a lot of times to normalize my PC and that has been a lesson to me so far.


Ok, let's return to the main subject. Here are computer viruses classified as the worse ones.
Look over below if you are familiar with them.


Brain, 1986
It all started here: Brain was the first "real" virus ever discovered, back in 1986. Brain didn't really hurt your PC, but it launched the malware industry with a bang and gave bad ideas to over 100,000 virus creators for the next 2 decades.

Michelangelo, 1991
The worst MS-DOS virus ever, Michelangelo attacked the boot sector of your hard drive and any floppy drive inserted into the computer, which caused the virus to spread rapidly. After spreading quietly for months, the virus "activated" on March 6, and promptly started destroying data on tens of thousands of computers.

Melissa, 1999
Technically a worm, Melissa (named after a stripper) collapsed entire email systems by causing computers to send mountains of messages to each other. The author of the virus was eventually caught and sentenced to 20 months in prison.

ILOVEYOU, 2000
This was notable for being one of the first viruses to trick users into opening a file, which in this case claimed to be a love letter sent to the recipient. In reality, the file was a VBS script that sent mountains of junk mail and deleted thousands of files. The results were terribly devastating- one estimate holds that 10 percent of all computers were affected, to a cost of $5.5 billion. It remains perhaps the worst worm of all time.

Code Red, 2001
An early "blended threat" attack, Code Red targeted Web servers instead of user machines, defacing websites and later launching denial-of-service attacks on a host of IP addresses, including those of the White House.

Nimda, 2001
Built on Code Red's attack system of finding multiple avenues into machines (email, websites, network connections, and others), Nimda infected both Web servers and user machines. It found paths into computers so effectively that, 22 minutes after it was released, it became the Internet's most widespread virus at the time.

Klez, 2001
An email virus, Klez pioneered spoofing the "From" field in email messages it sent, making it impossible to tell if Bill Gates did or did not really send you that information about getting free money.

Slammer, 2003
Another fast spreader, this worm infected about 75,000 systems in just 10 minutes, slowing the Internet to a crawl (much like Code Red) and shutting down thousands of websites.

MyDoom, 2004
Notable as the fastest-spreading email virus of all time, MyDoom infected computers so they would, in turn, send even more junk mail. In a strange twist, MyDoom was also used to attack the website of SCO Group, a very unpopular company that was suing other companies over its code being used in Linux distributions.

Storm, 2007
The worst recent virus, Storm spread via email spam with a fake attachment and ultimately infected up to 10 million computers, causing them to join its zombie botnet.

http://tech.yahoo.com/blogs/null/87095