Top 5 Most Popular Computer Viruses and Worms

And by popular we mean those that affected millions of PCs around the globe, leading to huge socio-economic damages. Throughout history there have been a lot of computer viruses and worms created, but in this article you will find some of the most dangerous. You can rate these computer viruses and worms as you like, since all of them are "good" candidates for the number one position.
Blaster computer worm
This is a computer worm that was developed to begin a SYN Flood against port 80 of windowsupdate.com. The worm intended to launch a Distributed Denial of Service attack against the website. After the worm has identified an Internet connection, it led to system instability and then the user could see the message that appeared for 60 seconds saying:
"I just want to say LOVE YOU SAN!!"
"billy gates why do you make this possible? Stop making money
and fix your software!!"
ILOVEYOU computer virus
Surely everyone has head of this computer virus. ILOVEYOU is believed to be one of the most dangerous malware among viruses, worms and Trojans in history, being developed by VBScript. For the first time the worm was identified in Philippines on May 4, 2000 and in a rather short period of time (basically one day) it managed to spread throughout the globe, damaging 10 percent of all Internet users and leading to a $5.5 billion loss. Everything started when an email message arrived in the user's inbox with the subject "ILOVEYOU". The message featured an attachment called LOVE-LETTER-FOR-YOU.TXT.vbs. After penetrating the system, the worm used to substitute all files with a copy of itself attached to each file on the computer. Besides, ILOVEYOU worm sent a copy of itself to all users on victim's contact list. This is the reason why the worm managed to spread extremely fast. Just like in previous case, the affected users were those who use Windows operating system.
Sobig computer worm
For the first time this computer worm was identified in August 2003. Just like all powerful viruses and worms this one affected millions of Internet users who work on Windows. It was created using Microsoft Visual C++ complier and compressed with the help of tElock. It was both a worm (because it used to replicate itself) and a Trojan Horse. Up till now the developer of this computer worm and Trojan Horse was not identified.
Virut computer virus
The goal of this computer virus is to infect executable portable files, including .exe and .scr. Every time it spread, the virus used Polymorphism in order to avoid being identified. After infecting a computer, the virus opens a backdoor, thus being able to connect to an IRC server. Using the backdoor, the hacker was able to download extra malware to the victim's machine. The Virut computer virus managed to shut down computers from the Texas court system.
Conficker computer virus
Spotted for the first time in November 2008, this computer virus managed to affect a huge number of computers. Conficker represents a worm that can replicate itself and spread very quickly mainly via a buffer overflow weakness in the Server Service on machines that run on Windows operating system. This computer worm can disable such Windows services as Windows Update, Windows Defender, Windows Security Center and Windows Error reporting. Today almost all antiviruses are able to detect this worm. The main countries affected by Conficker include China, Argentina, Brazil, Russia, and India. link....