The most dangerous computer viruses

1. Commwarrior-A

Hello iPhone users; welcome to the next level of viruses. Commwarrior-A began attacking in the summer of 2005, and it hit ... cell phones. Interestingly, the very first cell phone virus spread through text messages. Security experts see Commwarrior-A as the beginning of a new kind of virus, and worry that the proliferation of smart phones means Commwarrior-A was simply the first in a new kind of virus.

2. Welchia

Welchia remains one of the most unusual worms in history as it was designed to help, not harm. An interesting fact is that it was designed to detect the Blaster virus program, but it did not behave as planned - it infected all computers, killed the virus and destroyed itself.

3. Blaster

The detonator was not a particularly dangerous worm, but received a lot of media attention. The worm found a security hole in Windows XP and wrote on the screen reading "Billy why is this possible, stop making money and fix your software!" An 18-year-old boy named Jeffrey Lee Parson was arrested and eventually sentenced to one and a half years in prison for bullying Bill Gates.

4. Slammer

Prison is an extremely fast-spreading computer worm that infected 75, 000 computers in ten minutes. An interesting fact is that the creator of the worm managed to squeeze only a couple of hundred bytes into its code.

5. Nimda

Nimda was a rare combination of a worm, virus, and Trojan horse. “NIMDA was a Windows virus that had many different methods of infection. It used email, web servers, all kinds of contact. This allowed it to become the most prevalent virus in the world less than an hour after it was released.

6. Creeper

Written in 1971, Escape was the first computer virus. It infected a PDP-11 computer, Department of Defense. After infection, the computer showed a message: "I ran, catch me if you can!"

7. Elc Cloner

Written in 1982 by a high school student, Elk Cloner infected I Apple II computers via a floppy disk. At every 50th boot, the virus forced the computer to display a poem written by a hacker.

8. Moris Worm

Robert Maurice wrote his virus when he was a student, for which he became the first person to get a sentence for computer fraud and abuse. Maurice is currently teaching computer science at one of the universities.

9. I love you

The original ILOVEYOU mail virus damaged millions of infected computers. The e-mail received letters supposedly from lovers, containing the virus code. Since March 4th, 2000, the virus has infected more than 50 million computers in nine days, and - an interesting fact - forced the CIA and the Pentagon to shut down their computers.

10 Code Red

This worm, in July 2001, infected 360, 000 computers in one day. The worm attacked Microsoft IS servers and caused a host of service problems.