List of 5 Worst Computer Viruses and Worms in the History

Computer viruses are the real-life nightmares of technology lovers. The fear of having our system corrupted by different viruses always revolves around us. These viruses not only disturb the functioning of our devices but also create a havoc. Sometimes the damage caused by these viruses, also known as worms, is irreplaceable. The technological development leads to the discovery of more dangerous and deadliest viruses. From Elk Cloner, the first virus to be created, to Flame- a virus came into action in May 2012 we see a new level of advancement.

John Von Neumann was the first person who described what the virus actually is. In 1949, Neumann gave lectures at the University of Illinois about the “Theory and Organization of complicated automata”. In his research, he talked about the self-replicating programs. He described how a computer program could be designed to reproduce itself. Because of his theory and essays on viruses he was known as the Father of virology.

An interesting name with interesting features- BRAIN, the first ever known virus was discovered. Two Pakistani brothers residing in Lahore created the virus Brain. Basit Farooq Alvi and Amjad Frooq Alvi were the creators of this virus. Brain-targeted the memory space of the system. It slows down the floppy disk drive and makes a specific amount of memory unavailable. Although brain lacks code for dealing with hard disk partitioning, it got really famous then. In 2011, almost 25 years later, Brain was released. Mikko Hypponen of F-Secure Corporation, cybersecurity and privacy company went to Pakistan to interview the brothers for a documentary. Also, the two brothers were interviewed under the banner of Bloggerine.

List of 5 Worst Computer Viruses and Worms in the History

From 1949, the beginning of virus’s history initialized. Creeper system came in 1971, ANIMAL by John Walker in 1975, Elk Cloner by Richard Skrenta, and many other. The discovery of computer viruses is a never-ending development. Some viruses were easy to handle but some were very complex and hard to decode. Let us have a look at some deadliest computer worms and viruses around the world.



David L Smith, the man who created this deadliest virus in 1999. There is a very interesting background story behind Melissa. David created Melissa in such a way that it was an infected word document claiming to contain a list of passwords for more than 50 pornographic sites. People were curious when downloaded the file got trapped in the virus. When the word document was downloaded, it would unleash its payload. The virus will mail itself to the top 60 people in the user’s email address and would again cause more damage. According to the survey, Melissa caused more than $80 million in damage across the world. David Smith was arrested but later because his cooperation and talent of finding more hackers and viruses were bailed.



Wannacry is estimated to have affected more than 200,000 computers worldwide. The total damage wanna cry caused was ranging from hundreds of millions to billions of dollars. This was among those viruses whose damage was not only related to computer systems but people had to suffer huge financial losses because of it. This worldwide cyber attack was discovered in May 2017, which targeted computers running the Microsoft Windows operating system by encrypting data and above that demanding ransom payment for the data to be given back. The hackers also had some rules regarding the ransom payments. If the ransom which was asked in Bitcoin cryptocurrency was not made within 2 days the ransom amount was doubled and if more delay was made then the data was permanently deleted within a week. Wannacry was so deadliest that even the government officials closed their systems for few days. Wannacry is one of the most dangerous viruses of all.



In 2002, the ILOVEYOU virus obtained a world record for being the most virulent computer virus at the time. It is hilarious that a virus after affecting your system drops a message on your PC “ILOVEYOU”. This virus was given different names like love bug or love letter. ILOVEYOU virus is somewhat similar to Melissa, it also opens your account and replicates itself. This virus was created by two computer science students from Filipino, Reonel Ramones and Onel De Guzman. This is one of the most damaging worms ever. All the charges were dropped on the two students because they were not involved in stealing or any other serious cybercrime.



Flame is a very sophisticated malware also known as a flamer, skywiper, etc. In May 2012, the flame was discovered by Iranian national computer emergency response team (CERT), MAHER center. Flame exploited many security vulnerabilities. Flame is a very clever kind of a virus, it can transform itself into anything to save itself from being detected. The malware determines what antivirus software is installed in the system, then it customizes its own pattern by changing the filename thus reducing the probability of detection by that antivirus software.



The virus was created by a 17-year-old German Sven Jaschan who created two programs to unleash Netsky and Sasser onto the internet. Both Netsky and Sasser were very different from each other but the code was same. The virus spread in a different manner as compared to other viruses it did not spread via e-mails, instead, it attacked computers through Microsoft Windows vulnerability. The virus also altered the victim’s operating system in such a way that made it difficult to shut down the computer without cutting off power to the system. Sasser accounted for 25% of the computer infected worldwide.

I hope now you are aware of the dangerous Trojan horse, worms, viruses and would definitely try to save your computer system. Other deadliest viruses are Code Red, Zeus, Conficker, Mydown, flashback, etc. save yourself from these malicious computer programs and do not get trapped by hackers and cyber attackers.

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