Top 10 Computer viruses




Top 10 Computer Viruses, Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,



































Computer Virus is a common threat which all of us faces now days. A virus is basically a hidden code programmed to do something harmful or against the will of the computer it attacks. We try  to use one the best anti- virus available according to our data and computing needs .

Computer virus is a virtual disease which affect the pc in various ways for example, deleting and corrupting files, slowing down the speed of processing or operating, deleting system files, stealing/sending data without permission and making the pc freeze for a long time. These are relatively less harmful as compared to others. 


There are some viruses which have literally destroyed the computers of the modern world.Losses incurred annually because of viruses, both private and corporate, amount to millions of dollars.  Although there are innumerable types of viruses, there are some viruses which made their places in history books due to their huge amount of  loss brought to companies as well as personal computers all over the world. 


Some of the computer virus which can be considered in the list of top 10 worst computer viruses of the world are these.



10. Melissa

Melissa Virus, Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
The name looks very attractive and interesting but in reality it was one of the earliest mass mailing virus which was created by David L Smith. He created Melissa in the memory of a famous lap dancer who he liked. When the pc is affected by Melissa virus, it mainly targets Microsoft office files. It generates emails to send to contacts stored by using Microsoft outlook. Later on David L Smith was arrested and fined $5000 and spend 20 months in Prison.


9. ILOVEYOU

I Love You Computer Virus Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
It has been heard and told that these 3 words change the meaning of life but when it comes to a virus, trust me, it’s something very harmful for your computer. ILOVEYOU comes in a form of email with attachments on its back end and when the user see the mail with a title written ILOVEYOU on it, it obviously creates curiosity and encouragement to check and open the mail. Its actually a blank mail and ILOVEYOU spreads in to the pc and becomes a hidden file in almost all the folders of the pc in result of slowing down the system or corrupting a huge amount of important data or files.

8. The Klez Virus

The Klez Virus Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
The Klez is a computer Virus which spreads through email having one or couple of attached files which spreads like fire in the system and start damaging files again and again. Sometimes the antivirus is not able to fix it. Once The Klez Virus spreads in the system then it starts sending emails and instant messages to the contact list or address book. The Klez also spreads instantly over the shared network folders and can damage files on them.

7. Code Red and Code Red II

Code Red and Code Red II Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,  
Code Red and Code Red II is one of the most dangerous virus developed in the history. When the servers or computers become infected by Code Red and Code Red II, a message appears on your screen or LCD like  ”Hello, Welcome to http://www.worm.com” . One of the major loss done by this virus is this that it infected the white house pc as well. The approximate damage caused by Code Red and Code Red II to the world is more than $2.5 billion.

6. Nimda

Nimda Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
Nimda is a virus which has damaged most of the computers of the world and it first surfaced in 2001 and affected windows severely. If we do some math and calculate the total damage caused by Nimda, then roughly the costs due to damage is found out to be more than $620 million. The main targeted victims of this virus were internet servers and websites. Nimda also spread through emails.

5. SQL Slammer/Sapphire

SQL Slammer Sapphire Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
SQL Slammer/Sapphire is one of the most serious and dangerous virus till now. On 25th January 2003, it attacked the world very fast and within 10 minutes it affected 75000 + computers worldwide. The targeted victims of this virus were mostly the internet hosting companies and it also slowed down the speed of internet.

4. MyDoom

MyDoom Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
MyDoom is a type of email computer virus and spreads all over the pc very fast. In MyDoom a file is attached to the email which gets downloaded automatically at the time when user opens the email or clicks on the email. After that MyDoom starts to expand from pc to pc sharing programs and it is very dangerous for computers running on Windows. MyDoom has caused a serious loss in internet history in 2004 by making the internet speed as slow as to 50 %.

3. Sasser

Sasser Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
Sasser virus has also been famous all over the world. Sasser spreads throughout the system in very less period of time. Although it can be stopped by a firewall. This virus has caused a huge loss to many big companies. When a pc in affected by Sasser mostly it happens that the pc gives an error of restarting after one minute itself and there is no way to stop it whatever work you are doing that has to be closed before one minute so that the data should not be lost.

2. Leap-A/Oompa-A

Leap-AOompa-A Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
Leap-A/Oompa-A was created in 2006 and is considered as one of the most dangerous viruses of the world. Leap-A/Oompa-As has a way of affecting system through ichat instant messaging. After the Leap-A/Oompa-A affects the system it search for other computers through ichat contacts and then send them a simple jpeg picture file which looks a common file but on the back end of the file there isLeap-A/Oompa-A.once the user or viewer accepts the file then the computer virus is transferred in to his system and this happens so on. That’s why it is not advisable to accept picture files in chat rooms from unknown people.

1. Storm Worm

Storm Worm Computer Virus Computer, viruses, Melissa, ILOVEYOU, The Klez Virus, Code Red and Code Red II, Nimda, SQL Slammer/Sapphire, MyDoom, Sasser, Leap-A/Oompa-A, Storm Worm,   
In the ranking list of top 10, Storm Worm is the most dangerous computer virus which came in the history of internet. It used to come with the emails and the time when you open the email Storm Worm spreads in the entire computer and start destroying important files and documents in your hard drive. Once your pc is affected by Storm Worm then there is a huge loss in terms of valuable files and data.


Note: The following is a research for information and educational purposes only but if you think that there is something which you know better then you feel free to comment about it. Our team will look in to it and if your information is valid and accurate and suits the ranking then we will display it by your name.