7 of the Worst Computer Viruses Will Show You What to Protect Against Do You Know What Your Antivirus Is Really Protecting You From?

It is interesting to imagine how the virtual landscape used to look like at the beginning of the digitalized era. People were still pretty excited with the capacity of being online, connected with others across the globe. Yet this opened computers to a series of threats which were pretty real back then as well. It seems that the access to a network of connected computers intrigued not only those who wished to communicate, but also those who wished to see how far things could go. Computer viruses have been around since then and only by understanding what they are, we learn to appreciate the effort made by antivirus program developing companies.

7 of the Worst Computer Viruses of All Time


E-mail containing the Melissa virus
E-mail containing the Melissa virus

Although not created to do harm, Melissa spread so fast and to so many computers that giants such as Intel and Microsoft had to shut down their e-mail servers for a while only to stop spreading it. The virus was created in 1999 by Adam Smith and it was named after a stripper from Florida. You got an e-mail from a close friend with a word list document and a text saying you asked for this document and not to show it to anyone else. The document was supposed to contain passwords to over 80 pornographic sites. Upon opening the list, the virus e-mailed itself to the top 50 contacts in your address list and even corrupted some of your files by inserting Simpsons quotes. The virus manages to overload and block servers in the public and private sectors on account of its very fast spread.


Another virus hidden in an infected text was the ILOVEYOU virus and it was released only one year later. Disguised as a love confession, the virus was sent as an e-mail from someone in your address list. Once clicked, it sent itself to other people in your address list and overwrote files with itself. This time, however, its creators, two Filipino men, Reonel Ramones and Onel de Guzman, actually wanted to get computer passwords from those infected.

E-mails containing the ILOVEYOU virus
E-mails containing the ILOVEYOU virus


An 18 year old German boy, Sven Jaschan, made a gift to the world on occasion of his coming of age and released a virus that crashed your computer and forced you to unplug it to shut it down. A lot of organizations were affected and the electronic infrastructure of airlines, news agencies, public transportation and other such institutions crashed. The damages were estimated around $18 billion.


Thought to still be active in some form today, MyDoom was the fastest spreading worm since ILOVEYOU. You could get it via e-mail, masked as a wrong transmission. When you opened it, it automatically sent itself to your contacts, copied itself to any P2P program and it spread inside the network. The estimated damage of the virus rose to $38,5 billion with the SCO Group being the intended target of the attack, allegedly over a dispute on a Linux code ownership.


E-mails containing the StormWorm
E-mails containing the StormWorm

This virus posed as e-mails with pieces of news on storm reports from Europe. It infected millions of PCs in 2007 and it allowed hackers to access them, steal passwords, spam and steal identities. It seems that the idea behind the creation of this virus was to enslave all the computers in the world and to have these bots transfer their information. Once a computer was infected, it tried to infect others as well. Antivirus program developing companies detected the threat and tried to stay on top of the problem, but the creators of the virus kept changing the code, making it difficult to detect. It was eventually contained, however.

6.SQL Slammer

This virus worked incredibly fast. It managed to infect the first 75,000 computers in only 10 minutes. The rest were infected in a matter of seconds. In 15 minutes, SQL Slammer had managed to infect almost half the servers used for the Internet. And this was in 2003. One interesting feature about this virus is that is only attached systems on SQL servers and it avoided home computers. Once again, public domain structures like 911, airports, banks, public transportation were affected.

7.Anna Kournikova

This is a virus that was mentioned in the Friends sitcom because it had become so well known. Dutch programmer Jan de Wit created a virus which came to your computer via e-mail. You were suggested to open a link that allowed you to catch a glimpse of the curvy body of Anna Kournikova. The virus then took control of the e-mail address book and unleashed an avalanche of e-mails that paralyzed the servers.

E-mail containing the Anna Kournikova virus
E-mail containing the Anna Kournikova virus

So next time your antivirus program asks for an update, or if you travel a lot and you work from several public Wi-Fi networks, do yourself a favor and update your protection program or get a good, paid one. It would be a shame to lose all your hard work on account of a virus you picked up by connecting to the wireless network at the airport. And make no mistake! Antivirus companies are making great efforts to keep up and meet modern day expectations when it comes to viruses, but the people creating viruses are just as creative and well informed.

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