The most dangerous computer virus in the world. Overview and description of computer viruses

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The most dangerous computer virus in the world. Overview and description of computer viruses
The most dangerous computer virus in the world. Overview and description of computer viruses

Viruses from the very beginning of the creation and development of computer technology have become quite widespread. Some of them were and are completely harmless, the damage from impact on computer systems from others is estimated at billions of dollars. History knows many examples of the manifestation of viral activity, which led to real epidemics, infecting user PCs and performing their destructive functions. The following is a brief review of the most dangerous computer viruses in the world, which at one time had the most tangible impact on computer systems around the world.

What is a virus in terms of computer technology?

In general, computer viruses do not mean some abstract concept, but the most common software that affects a computer system (in particular, an operating system, applications installed in its environment oruser files) with the aim of causing harm, stealing data, extorting payment for decrypting files, etc. These programs themselves contain special executable codes that are activated either directly upon penetration into the system or at a certain point in time, but aimed at launching completely different operations. First, the main code is intended for the main action for which the virus itself is designed. Secondly, parallel processes are very often launched, allowing viruses to hide from the eyes of the user or anti-virus software (disguise themselves), working in the background and replacing some system components with their own applets. Thirdly, along the way, operations for self-copying, embedding code into installed programs, sending themselves over the Internet or over a network, etc. can start.

There are a lot of known types of virus threats today, and the list of their types by classification looks quite impressive (trojans, worms, ransomware, ransomware, ste alth viruses, polymorphic applets, spyware, keyloggers, resident or non-resident threats, and many others), not to mention the fact that some types of threats cannot be attributed to any one class. However, if we talk about the most dangerous computer viruses in the world, almost all of them belong to the category of worms. At the dawn of the development of computer technology, they penetrated the system mainly through removable media (floppy disks), but with the advent of the Internet, they began to be transmitted by e-mail or settled on various sites on the World Wide Web.

The most dangerous viruses in the worldfor computer

The statement that viruses, as a threat to computers, arose at the time the technology itself appeared in the form of home PCs, looks completely wrong. The fact is that such technologies began to be actively developed in the early 50s of the last century. By 1961, even the Core War movement had formed among programmers, which is a kind of competition for the inconspicuous destruction of each other's programs. But the official date of the appearance of the threats that are now called computer viruses is 1981, when the Elk Cloner and Virus 1, 2, 3 viruses were created, the codes of which were designed to run on Apple II computers. Subsequently, the bulk of threats began to target mainly Windows and Linux systems, although it is believed that Linux and Apple OS are more resistant to their effects. The progenitor of all known threats today is the notorious Brain virus, which made a lot of noise in 1986. At the moment, there are several main threats that are considered to be the most dangerous in the entire short history of the existence of computers, among which the most famous are the following:

  • Brain.
  • Jerusalem.
  • Morris Worm.
  • Michelangelo.
  • CIH ("Chernobyl").
  • Melissa.
  • ILoveYou.
  • Nimda.
  • Code Red.
  • SQL Slammer.
  • Sobig F.
  • MyDoom.
  • Conficker.
  • StormWorm.
  • Petya.
  • WannaCry.


This software was originally created by two brothers-programmers from Pakistan and the nature of the virus was not. This applet was only supposed to punish users of their own unlicensed software by removing installed applications from their computers.

Virus Brain
Virus Brain

But, as is usually the case, the virus got out of control and infected several tens of thousands of computers around the world (18,000 in the US alone). It replaced boot infected entries with neutral ones, and therefore attempts to detect it were absolutely futile until a certain time.


No less dangerous and malicious was a virus applet called Jerusalem, which in 1988 was most widespread in Europe, the USA and the Middle East. The essence of its impact was that infected executable files were immediately deleted when they were tried to run. But the side effect looked much more unpleasant. If the 13th fell on a Friday, the virus applet would spontaneously start a full format of the hard drive.

Morris Worm

This virus is called almost one of the most ingenious creations, which was created by a 23-year-old student from the USA in the same 1988.

Morris Worm
Morris Worm

His action looked twofold. On the one hand, he was able to guess passwords for accessing operating systems using a dictionary containing only 400 words. On the other hand, he brought computers to a state of complete dysfunction, constantly copying himself and sending copies over the Internet. The total damage at the time was estimatedapproximately $100 million. It is also noteworthy that if Morris had not admitted his authorship of this applet, the creator would never have been found. By the way, in essence, this virus can be called the first network worm (it spread over the ARPANET network).


This virus, by its nature, did not pose any danger from the very beginning, because after penetrating computers from floppy disks, it remained inactive until a certain moment and waited for the right moment to attack. Michelangelo's birthday, March 6, became such a moment. On this day, the virus activated in the system and destroyed absolutely all data stored on the hard drive.

CIH ("Chernobyl")

In the same 1988, another applet called CIH, created by a Chinese programmer, was born. The name was formed from the first letters of his name, and behind the scenes the virus began to be called Chernobyl due to the fact that it became more active just on the anniversary of the accident at the Chernobyl nuclear power plant (April 26). It was most widespread in East Asia, but its impact on computers looked already more destructive.

CIH virus
CIH virus

The fact is that he not only deleted information on the hard drive, but also completely erased the BIOS shell. About 300,000 computers were officially confirmed to be infected, and according to tacit information, the total number of affected PCs was at least half a million.


One of the most dangerous computer viruses in the world is still considered to be the notorious Melissa applet, which has doneat one time a lot of noise in 1999.

Melissa virus
Melissa virus

The virus attacked mail servers, looked for email addresses on user computers (the first 50 in the address book) and sent out not only its own copy, but also letters with content that today would be classified as spam. In some ways, the impact of the Melissa virus on mail servers was similar to what is today called a DDoS attack. Thus, their work was completely paralyzed due to overloaded systems, and the total damage amounted to about $100 million.

ILoveYou virus

2000 added turmoil to the computer world. It is this time that is associated with the appearance of one of the most harmful viruses, ILoveYou. It spread all over the world via email.

Virus I Love You
Virus I Love You

Recipients received a letter with an attachment disguised as a text file with a declaration of love. The subject of the message and the title of the attachment just indicated I Love You. In fact, the contents of the attachment were the most common executable script written in Visual Basic, which, after being launched, not only destroyed files on the hard drive or in a network environment, but sent copies of itself to all contacts from the address book. The creators of the I Love You applet turned out to be very resourceful and played on human weaknesses (who doesn't wonder who confesses their love to you?). Experts estimated the total damage from infection at about 10-15 billion dollars. By the way, in terms of the scale of spread and infection, the virus was included in the "book of recordsGuinness" as the most dangerous threat of our time.

Nimda is another virus

The multi-vector worm Nimda (the name is the word Admin spelled backwards) was seen by the world in 2001. It used several basic network and Internet distribution techniques to hit millions of terminals in just 22 minutes. At the time, it was considered the most famous Internet worm.

Code Red

Another virus that has made noise in the world is called "code red". It infiltrated computers through browsers linked to the Microsoft IIS web server.

Virus Code Red
Virus Code Red

Its effect was to replace system components with its own infected files, and after its activation in a computer system, the line “Hacked by the Chinese!” appeared on the monitor screen. with an invitation to visit It is noteworthy that the virus hit even the computers of the White House, and was created by ethnic Chinese from the Philippines.


SQL Slammer is a worm that infects both Microsoft servers and 500,000 other servers worldwide in 2003.

SQL Slammer Virus
SQL Slammer Virus

Due to the high speed of distribution and the impact of the type of DDoS applets, it literally in a matter of minutes significantly reduced the bandwidth of servers, and South Korea was isolated from the Internet for as much as 12 hours. It took a record short time to defeat - in just 10 minutes, about 75 thousand computers were infected!

Sobig F

The Sobig F virus in 2003 installeda kind of infection record. Nearly a million computers were affected.

Sobig F virus
Sobig F virus

Like the infamous "love" applet, it was distributed via email attachment, and Microsoft even set up a $250,000 reward for providing at least some information about its creators, who have not been installed to this day. As a result of the impact, damage was estimated at 10 billion dollars.


The MyDoom virus of 2004 is almost a complete analogue of the previous threat, but it broke its record in terms of spread rate and number of infected systems.

MyDoom Virus
MyDoom Virus

Its impact mainly affected Windows computers and came down to the fact that users could not access anti-virus application sites, open news feeds, or even access some sections on official Microsoft Internet resources.


A real storm in the form of enhanced DDoS attacks broke out in 2009, when the Conficker virus appeared. The description of its impact is as follows. The applet, after penetrating both computers and even smartphones, seemed to combine their computing capabilities into a single whole, after which it attacked the selected resources. The damage from its impact is expressed in almost an astronomical amount - 9.1 trillion dollars!


This virus applet is considered to be a kind of botnet designed to carry out DDoS attacks. The time of its appearance is attributed to 2007, and as creators oftenname programmers, presumably having Russian roots. According to preliminary estimates, about a million computers around the world were infected, and it was clearly created by professionals who used the most advanced computer and network technologies at that time.


This applet is one of the most recent and dates back to 2016. Its first modifications only blocked access to data on computers by encrypting files, when a certain amount was required for decryption. In other words, this applet became both a ransomware and ransomware at the same time. However, the latest versions of the virus "learned" to infect the boot records of the Windows operating systems themselves. It is believed that these were only test attacks, and the real full-scale impact should be expected in the near future.


Finally, this virus looks very similar to the previous threat, but requires only cryptocurrency (bitcoins) as payment, transactions with which are almost impossible to track in most known financial settlement systems.

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