The term virus denotes a threat to a computer system, It got the name virus because of its ability to spread across other system within a short period of time. Here are a few computer virus that had wrecked havoc on organisations and individual computer systems over time…

Storm Worm

It was discovered in 2006, One of the most dreaded virus of all time. It sends users emails with a subject line saying ‘230 dead as storm batters Europe’. It was said to have been responsible for 8% of worldwide computer -related malfunctioning.


Discovered 2000, It was termed as the most dangerous computer virus ever created. It was created It was a standalone program capable of replicating itself.

It use social engineering to get people to click on the attachment; in this case, a love confession. The attachment was actually a script that poses as a TXT file, due to Windows at the time hiding the actual extension of the file.

Once clicked, it will send itself to everyone in the user’s mailing list and proceed to overwrite files with itself, making the computer unbootable. It was believed to have affected over 10% of computers in the world.


Built in 1999, by David L Smith. The virus tempts recipients into opening a document with an e-mail message like “Here is that document you asked for, don’t show it to anybody else.” Once activated, the virus replicates itself and sends itself out to the top 50 people in the recipient’s e-mail address book.

Code Red

It was discovered in 2001, by two eEye Digital Security employees. It was named code Red because they discovered the virus while drinking Code Red Mountain Dew. The worm targeted computers with Microsoft IIS web server installed, exploiting a buffer overflow problem in the system. It leaves very little trace on the hard disk as it is able to run entirely on memory, with a size of 3,569 bytes. Once infected, it will proceed to make a hundred copies of itself but due to a bug in the programming, it will duplicate even more and ends up eating a lot of the systems resources.


Got its name from the backward spelling of ‘ADMIN’. It was discovered in 2001, It was the fastest propagating computer virus at that time (It takes only 22 minutes to spread through emails, servers, shared folders and files). The Nimda worm’s primary targets were Internet servers. While it could infect a home PC, its real purpose was to bring Internet traffic to a crawl. It could travel through the Internet using multiple methods, including e-mail. This helped spread the virus across multiple servers in record time.


This is a very dangerous virus ever created or founded because of its only damage industrial computers. This virus can not affect the normal people system or not its intention to damage normal system. This virus had stopped one-fifth of the Nuclear Centrifuges which is part of Nuclear Power Plant in Iran. This Stuxnet virus had identified in the year of 2010.


This virus made for the purpose to hack or insecure the security system. This virus attacks the local authority security systems. This Sasser virus also mainly attacks Windows-based operating systems. This virus is very lethal for an operating system which has critical infrastructures. This virus damage privacy of millions of the people and also the money of these people’s. According to survey this Sasser virus damage billions of the dollars in the year.


It was first identified in 2009. It was a Trojan horse made to infect Windows computers so that it will perform various criminal tasks. The most common of these tasks are usually man-in-the-browser keylogging and form grabbing. The majority of computers were infected either through drive-by downloads or phishing scams.


Surfacing in 2004, Mydoom was a worm for Windows. The author is unknown and it is believed that the creator was paid to create it since it contains the text message, “andy; I’m just doing my job, nothing personal, sorry.” It was named by McAfee employee Craig Schmugar, one of the people who had originally discovered it. ‘mydom’ was a line of text in the program’s code (my domain) and sensing this was going to be big, added ‘doom’ into it.

What other deadly computer virus do you know? Have you been a victim before? please share your ideas…