What Are The Top Computer Viruses?

The history of computer viruses began in 1983 when the first of them was written. An American student did this and after this, many other similar programs begin to appear one after the other. Most computer bugs are very small, but some of them have caused great damage to both ordinary people and large corporations, and even countries.

computer virus

As for anti-virus programs, they were launched only in 1988. Since then, this field has also developed significantly, and these days, company cyber security things are very important. We must remember both the dangers and the prevention. So, let’s discuss both questions.

The most famous computer viruses

In fact, there are more than 10 types of computer viruses. However, the top 10 are known for the damage they caused.

My Best Wishes

This PC virus appeared in 2004 and was very destructive. It caused more than $38 billion in damage. In addition, there were some lasting unpleasant effects from his attack.

The virus gave attackers access to the computers and installed programs. It affected emails.


This virus was inside email attachments. When the latter was opened, a copy was automatically sent to the contacts. It also made some malicious system changes. It happens in the following way:

  • The letter was sent in 2000 from the Philippines.
  • The theme was ILoveYou, and the script was attached.
  • Since the expansion of the virus was hidden, most users did not expect anything to go wrong.

It included more than 3 million computers worldwide in total. The estimated cost of the damage was $10-15 billion.


Among various computer viruses, this one is a 500-kilobyte device that once infected the software of at least 14 industrial enterprises in Iran, including a uranium enrichment plant.


In 2003, this virus caused more than $37 billion in damage. He quickly distributed via email:

  • After opening the letter, he entered the computer.
  • It copied files, sent emails, and damaged software and hardware.


This one caused a lot of problems in 2004, resulting in $500 million in damage. In addition, the British Coastguard’s mapping system was destroyed by it. A teenager from Germany created this harmful program.


Cryptolocker is a ransomware virus that was released around the beginning of September 2013, targeting all versions of Windows. This was a new, dangerous computer virus.

Like other beggar viruses, CryptoLocker locks, in this case, encrypts, information on the hard drive and asks you to pay money to access it again. It was a novelty for such viruses to put a time limit on the ransom – users have three days to pay $300, €300, or 2 bitcoins before the key is released. encryption will be destroyed forever and the information will be lost. In order to feel that a refund is inevitable, a timer is displayed, counting down the time until the key is destroyed.


WannaCry is a ransomware virus that became widespread in 2017. It is a modified version of the US National Security Agency’s Eternal Blue malware.

Code red

The virus was launched in 2001 and infected 360,000 computers, creating a botnet to attack the White House website. After the attack, a message appeared on the screen with the words ‘Hacked By Chinese!’.


ZeuS (or ZBot) was a new type of Trojan that appeared in 2007 and is designed to attack servers and intercept data.

The Trojan was intended for all versions of Windows, and because of its structure, which allows it to work without connecting the program to drivers, it can capture a computer even from a host account.

After entering the system, the program enters the user’s registration data and is able to transfer money to other victims’ accounts in small amounts, which makes it -possible to find and monitor the resources of hackers.


Slammer, which appeared in 2003, mainly affected the automated systems of banking institutions, causing an estimated loss of $750 million. In total, more than 200 thousand computers around the world succumbed to the action of this virus. It also caused noticeable slowdown in internet connection.

Viruses vs worms

Sometimes they are called computer bugs, sometimes viruses and worms. Actually, there is a difference between the last two options, which are:

  • A virus is a program that can enter a computer in a variety of ways and can cause effects ranging from simply annoying to destructive.
  • A worm is a program that is very similar to a virus. It is capable of self-replication and can adversely affect the system.

The main difference between them is that worms are able to reproduce on their own. They do not rely on files on the computer or boot sectors. Worms are sent using email addresses from the victim’s contact list or exploiting vulnerabilities in various applications for this.

Because of the ubiquity of the Internet, worms often spread rapidly around the world within hours or even minutes of their appearance. This ability makes them more dangerous than other types of cyber threats.

How do you know if your computer has a virus?

Slow performance, application crashes, and freezes can sometimes be a sign that a virus or other form of malware is interfering with your computer. However, many other issues can slow down your PC.

Some applications quickly pop up a command window when updating, so strange windows may pop up on your screen and disappear quickly like a normal piece of software and not It is a sign of malware. Similarly, just because your computer is working fine, doesn’t mean the device is free of malware.

Today’s viruses usually hide in the background to avoid detection, and can easily steal your personal information, such as passwords, credit card details, etc. well designed viruses will not cause any noticeable problems with the PC at all.

Sometimes malware causes problems with the PC, and sometimes it behaves well. However, a sudden slow PC performance could be one of the signs that you have a virus on your computer. The only way to know for sure if a device has malware is to scan your system completely and then clean the computer of viruses.