10 Worst Computer Viruses


Viruses are the deadliest threat to a computer. It is not only for a computer, but also for the information and data in it. Even worms, Trojans and spam can be considered in this category. For example a virus can empty a bank account in minutes without the account holder’s permission. Let’s have a look at the worst of all these viruses.
1. The Morris worm

This was created by Robert Morris in 1998. This virus affected around 60,000 computers which was around 10 percent of all the computers used internet in those days. He was a student of MIT at that time and this program was not supposed to be a virus. But it halted the working of all the computers it went in. Now he is an associate professor in the same university. He sent this virus as if it is sent from MIT. It exploited the weaknesses in passwords, in UNIX and also in Finger.

2. The Concept virus

This was not a planned virus attack. It was accidentally copied in a CD-ROM which was shipped by Microsoft in the year of 1995; it started damaging Microsoft word files very fast. Since the word files are used most frequently, it started spreading very fast through e mails as well. This was the fastest to spread among all the viruses.

3. CIH

This will trigger on 26th of April every year, on the day that Chernobyl incident happened. This virus is named as the Chernobyl virus and was created by Chen Ing Hau who was caught later on by Taiwan authorities. It will overwrite the chip of the computer and completely crash the computer.

4. The Anna Kournikova worm

This worm uses a picture of the tennis player Anna Kournikova as the medium to spread the worm. When the picture is opened it will install the worm in the computer. This worm was designed by Jan de Wit from Netherlands, who is a great fan of the tennis player. Finally he got sentenced for community service.


This was made by a Filipino person to get internet access passwords of the users. It will come as an I LOVE YOU message to the inbox and if opened will get forwarded to the full address book contacts automatically.

6. The Melissa virus

The Melissa virus was first found in March 26 in 1999. It was designed by David L Smith in homage a stripper from Florida. It also contained a quote from The Simpsons. It will shut down the mail systems that are affected by the virus. Even though it was not intended to damage the systems, finally it went out of control and created around $80 million of damage. Finally the man got sentenced to jail.

7. The Blaster Worm

It is a virus that found a way into Microsoft software with a security flow in Microsoft. Author is still unknown for this. It attacked the Microsoft website in the year of 2003 with a service denial.

8. Netsky and Sasser

This worm was designed by a teenager from Germany named as Sven Jaschan. He was a major malware spreader at that time. He was responsible for almost 70 percent of viruses spreading around the time. Surprisingly he escaped jail and started working as an ethical hacker in a security firm.

9. OSX/RSPlug Trojan

It was the first malware that came up against Apple Macs with a financial purpose. It came out in year 2007. This worm has put doubts in every ones mind about the security of the Apple platform against Trojan attacks.

10. Storm worm

It came to the users as breaking news of some bad weather in Europe. That made many of them to open it. Storm worm infected so many computers in 2007. It will allow the hackers to take over the computer and to extract confidential data from it.