Top 15 Most Destructive Computer Viruses in History


No matter how awesome your anti-virus software is, it will never be 100% virus and malware proof. Millions of hackers (and some governments) worldwide are working tirelessly to create the next supervirus that will bypass detection, spread fast and get access to all types of sensitive data. Although installing a solid anti-virus software is a good start, we can’t emphasize enough on how important it is to have an online backup or cloud storage solution to protect your data.

For the less tech-savvy users out there: a computer virus is a program, or a piece of code that can replicate (copy itself) and has a detrimental impact such as accessing private data or corrupting the system. Viruses are often loaded into the computer system without your knowledge, and they usually run without your consent. All viruses are man-made, and they spread through portable devices, email attachments, malicious scripts in websites or files downloaded from the Internet.

Here is a list of 15 of the most destructive computer viruses in history:

1. My Doom (2004)

My doom, also known as Novarg, entered the malware world in January 2004. It spread through email from random addresses and subjects. This virus infected over two million computers and initiated an extensive coverage of denial of service attacks (DOS) that halted cyber activity for some time. The damage caused by this virus averaged $38 billion.

2. Iloveyou

Iloveyou, also referred to as Love Letter, is a worm that infected millions of Windows PCs on 5th may 2000. It started spreading from Philippines through email messages with the subject “I love you” with an attachment “Love-letter-for-you.txt.vbs.” the VBS extension was hidden in Windows machines causing unsuspecting recipients to think it’s an ordinary text file. When the attachment was opened, it activated the Visual Basic code that overwrote files and sent itself to all addresses in the Windows Address Book.

3. Dark Avenger

Dark Avenger was written by a Bulgarian in Sofia, and it was active in 1988-89. The virus spread not only in Bulgaria, but throughout Europe, Australia, and America as well. It infects the COM and EXE files. It is fast and affects programs both when they are executed and when they are created, opened and closed. The virus deletes random sectors on the disk and causes a permanent data loss.

4. Code Red

Code Red was a worm that was observed in July 2001. It infected computers that ran Microsoft’s IIS server. By 19th July 2001, the number of infected machines had reached 359,000.

5. Melissa

Melissa was created by David L. Smith in 1999. It was designed to spread through email messages. The virus tempts users to open an email with a message such as “Here is the document you asked for. Don’t show it to anyone.” once executed, it would send itself to the first 50 people in your address book.

6. The Klez Virus

The Klez virus was discovered in 2001 and continued to plague users for several months. It infected a computer through an email message, copied itself then sent itself to people in the user’s address book. The virus could disable the antivirus in the computer and pose itself as a virus removal tool.

7. Nimda

The Nimda hit the Internet in 2009 and became the fastest spreading virus of its time. The virus targeted servers with the aim of slowing down the Internet traffic. It spread through several methods including email, and this was the reason for its great success.

8. Sapphire/SQL Slammer

SQL Slammer brought down several vital systems on the Internet. It crashed the Bank of America ATMs, Continental Airlines, Seattle City 911 services and many others. The virus caused damages worth more than 1 billion. Only 15 minutes after its attack, the virus had infected nearly half of the major Internet servers in the world.

9. Gasser and Netsky

Once in a while, authorities track down a virus to its creator. Such was the case with Sasser and Netsky. These two viruses were created by a German 17-year old. They attacked computers with an MS Windows vulnerability and would replicate and spread to computers with a similar vulnerability.

10. Leap-A (Oompa-A)

The Leap-A virus, also known as Oompa-A, used the iChat instant messenger to spread through Mac computers. After infection, it sends itself to contacts in the iChat program. The message looks like a message containing a corrupt jpg file.

11. Storm Worm

The Storm worm first appeared in the late 2006. It was named the Storm Warm because it spread through email messages with the subject “230 dead as storm batters Europe.” some versions of this worm would turn computers into bots or zombies. As they are infected, they can be controlled by the creator of the worm.

12. Conficker

Conficker is a virus that spreads very fast and targets an MS08-067 vulnerability in the Windows OS. It first appeared in 2008 and since then, it has established a botnet infrastructure. Once infected, it disables automatic updates and other security features in the computer.

13. Jerusalem

The Jerusalem virus was discovered in the late 1987, and it infected DOS files. Its origin is uncertain, but some most people believed it originated in Israel. It infects both COM and EXE file types, and when executed, it remains in the computer memory long after the host program has been ended.

14. Pakistani Brain

Discovered in 1986, the Pakistani Brain was reported to be embedded in software packages as a warning to those who pirate software. It infected IBM computers and copied itself to diskettes which were inserted into infected computers. It contained a message warning users to beware that their computers had been infected and to contact the creators for a vaccination.

15. Creeper

Creeper is recognized as the first computer virus ever. It was created by Bob Thomas in 1971 as an experimental, self-replicating program that was not intended to cause any damage. The virus corrupted DEC PDP-10 computers running the TENEX operating system. It displayed the message “I am the creeper, catch me if you can!”

Virus attacks are dangerous to your data and the proper performance of your computer. Therefore, you need to have your data backed up using an online backup or cloud storage so that in case of a computer virus, you will not end up losing all your valuable data. You also need to invest in a proper antivirus program that will protect you from the most common viruses.

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