What is a computer virus and how is it dangerous? Computer virus and how it can be dangerous The danger of computer viruses

In search of protecting our data, we begin to think about how to protect our computer from third-party attacks with the aim of taking over our information. It’s about the types malware and viruses that attack our PCs, we will talk below.

Let's start with perhaps the most common habitat of viruses and malware - the Internet. Only at first glance it may seem that the Internet is a big, kind “world”, very friendly and diverse with many paths and roads into its depths. But it is precisely in this “Internet world” that millions of different dangers live, including Internet viruses.

The Internet today is not only millions of pages on a variety of topics, it is also an insidious place with viruses, malware, and spyware. And even if you limit your use of the Internet, viruses still have a good chance of getting in and infecting your data on your computer.

According to the history of PC development, viruses did not “lag behind” electronics in their development. “Virtual diseases” began to be developed back in the 80s of the last century. Back then, viruses were mechanical structures that could self-repair, activate, and capture new types of information. But over the past half century, viruses have come very far in their development and types; many malicious programs and individual dangerous viruses have appeared. In order to understand what viruses exist today and what threats they pose if they get onto your computer, we list them below by group:

Classic computer viruses – a type of viruses that begin their activity only when they are directly activated, i.e. when, for example, a user starts watching a movie or a photo or a song on the computer, then at that moment the hidden virus is activated and adds its code and begins to operate . This type of virus can enter or be transferred from one computer to another only when we copy a media file or program infected with it from one PC to another, or transfer the infected file on some medium (disk, flash drive, etc.).

The next type of viruses are Trojans . This is a very insidious type of virus, which carries a number of functions: failure of the PC operating system and all equipment in general; taking over PC resources for purposes contrary to yours; infection and destruction of data stored on a computer; capture and transfer of information stored on a computer to other persons.

Another type of virus is network worms. . Their task is to distribute their malicious copies to other PCs, as well as infect running programs with a virus. In addition, network worms can sometimes be characterized by the properties of Trojan programs

After we have decided on the ideas dangerous viruses, it’s worth thinking about how you can protect yourself from malicious attacks on your computer. Again, the question is not simple, but there are always options. For example, when purchasing anti-virus programs, you can rely on the advice of the software seller, become more familiar with existing ratings of security programs and reviews about them, and communicate with professionals in protecting your PC from virus attacks. And only after that should you choose a specific antivirus program. And even if later you are not satisfied with something in it, you can always replace it with another one.

The first computer viruses appeared immediately after the creation of computers. Programmers wrote them just for fun; such viruses did not cause any harm. But modern computer viruses are created for completely different purposes and pose a serious danger. What viruses exist and how to fight them?

All existing malware today can be divided into two categories: viruses and Trojans. The first ones simply perform some negative or humorous actions on the infected computer, for example, they can erase files or completely format the hard drive, turn off the computer, make the mouse inaccessible to the user, display some message on the screen, etc.

As a rule, the creators of viruses do not pursue selfish goals; most often such programs are written simply for entertainment. But there are exceptions - for example, viruses that block the operation of Windows.

The user sees a message in which he is asked to transfer a certain amount of money to a specific account, after which he will be sent an unlock code.

Having encountered such a virus, you should remember the features of the message, in particular, the account or phone number (if you are asked to top up your phone balance), then go from another computer to the websites of anti-virus companies and look for the appropriate unlocker. But even if you fail to remove the virus, the worst consequences from it are formatting hard drive PC.

The biggest danger is Trojans

This type of malware is created with the purpose of stealing a person's confidential data. If the work of a virus on a computer is usually clearly visible, then the Trojan program tries to completely hide its presence. Its task is to collect the necessary information, such as logins, passwords, bank card or online banking data, etc., and then quietly transfer everything to the owner of the Trojan.

High-quality Trojan programs are written by highly skilled programmers and can cost thousands of dollars. A well-made Trojan is absolutely invisible; no anti-virus program can detect it until data about the Trojan gets into anti-virus databases.

Modern spyware easily bypasses firewalls. Having done their dirty deed, many Trojans self-destruct, leaving no traces behind. You can only find out that your computer has been infected with a Trojan after money has disappeared from your bank card or it has been hacked. mailboxes, admin panels of sites you own, etc.

Backdoors

There is also a class of viruses called backdoors. Once the virus infects your computer, it creates a backdoor through which the hacker gains full access to the machine. He can view and copy information from disks, delete or add something. A hacker can use your computer to scan networks and hack other computers to launch attacks on servers. Thousands of hacked computers can be controlled from one center, in which case a botnet is formed - a network of infected computers subordinate to one person.

Viruses and Trojans pose a huge danger, so everyone fights them possible ways. The main problem is that the principles of construction and operation of the most common operating room today Windows systems provide hackers with plenty of opportunities to create and introduce malware.

OS developers are trying to close the gaps, but there are still too many of them. The operating room is much safer in this regard. Linux system It’s no coincidence that many hackers use it.

In any case, to protect against viruses and Trojans, your computer must have an up-to-date antivirus and firewall. You should also follow basic security rules - in particular, do not download or open suspicious files.

The concept of a computer virus is familiar to any user. Many people heard about certain “Trojans” and “worms” even before they had their first PC. And seasoned computer scientists always install an anti-virus program first, so that the system is maximally protected from malicious files that enter the machine from the outside. And if earlier, when the Internet was not yet so developed, the same viruses infected computer after computer, but they knew how to fight them. Now, with the development of the network, the range of malware is growing not by the hour, but by the minute, and it is becoming more and more difficult to fight them. No wonder antivirus databases are updated every day

What is a computer virus? Consequences of virus infection

But still, what is a computer virus? And is it transmitted by airborne droplets? If you look at various thematic encyclopedias, they have a clear concept.

A virus is malicious software that can reproduce in any operating system, destroying some important files, making changes to existing programs.

In a word, they “mess up” users’ computers. Ultimately, it becomes impossible to work with such a machine, the PC begins to slow down, behave strangely, upsetting its user in every possible way. Viruses work like surgeons - they penetrate the source codes of files and carry out their malicious operations there.

The virus creation industry began to actively develop with the advent of the Internet, since the World Wide Web is the easiest place for hackers to carry out their “dirty deeds.” The goals pursued by malware creators are very different. Some people do it just for fun, to practice writing programs. Most often, such “worms” do not pose a particular threat to the system, however, the creator himself does not always understand what his virus is capable of, so a harmless “worm” can sometimes become a real monster that devours system resources. The second category of people, engaged in the production of malware, pursues completely different goals, more specific - the theft of personal information from computers. Such viruses pose the greatest danger, as they are capable of stealing logins and passwords from some services, social networks or, much worse, from payment systems. The result is a hacked account, stolen money from electronic wallets and other unpleasant consequences.

The most famous viruses

Despite the huge number of viruses, among them there are the most famous ones that have infected a significant number of computers. The most “romantic”, but also one of the most dangerous “worms” was written by some Filipino guy. The hacker called his creation “I love you.” The essence of the virus was that, using the mail service, it sent letters to everyone, in the subject line of which it was written “I love you”, and the attached file contained the “worm” itself, which was stealing passwords. The “love plague” swept almost the entire computer world in 2008. According to various sources, the damage caused by the Trojan amounted to several hundred million dollars.

1) to crashes and freezes during computer operation (+); 2) to the loss of programs and data; 3) to format the hard drive;

15. Dangerous computer viruses can lead...

1) to crashes and freezes during computer operation; 2) to the loss of programs and data (+); 3) to format the hard drive;

4) to reduce the free memory of the computer.

1. What type of computer viruses are introduced and infect executive files with the extension *.exe, *.com and are activated when they are launched?

1) file viruses; (+)

2) boot viruses;

3) macro viruses;

4) network viruses.

1. What type of computer viruses are introduced and infect files with the extension *.txt, *.doc?

1. file viruses;
2. boot viruses;
3. macro viruses; (+)

1. network viruses.

1. Viruses that are introduced into a document under the guise of macros

1. Viruses that penetrate a computer block the operation of the network

1. Malicious programs that penetrate a computer using computer network services (+)

1. Malicious programs that install other programs secretly from the user.

1. Hardware.

1. Software.

1. Hardware and antivirus programs. (+)

22. Antivirus programs are programs for:

1. Virus detection

1. Virus removal (+)
2. Reproduction of viruses

1. AVP, MS-DOS, MS Word
2. AVG, DrWeb, Norton AntiVirus (+)
3. Norton Commander, MS Word, MS Excel.

25. Which programs are not anti-virus programs?

1. phage programs(+)
2. scanning programs
3. audit programs(+)
4. detector programs

1. Is it possible to update anti-virus databases on a computer that is not connected to the Internet?

1. Yes, by calling the technical support service of the antivirus program manufacturer. The specialists of this service will dictate the latest databases that need to be saved on your computer using any text editor

1. yes, this can be done using mobile media by copying anti-virus databases from another computer on which Internet access is configured and the same anti-virus program is installed, or on it you need to manually copy the databases from the website of the anti-virus program manufacturer (+)

Many users consider computer viruses to be either a completely useless, empty application that does nothing, or a program that “explodes monitors,” disables power supplies and removes all the money from the balance in the current bank account.

In this article we will try to figure out what to expect from a computer virus and what not to expect.

Let's start with what viruses now definitely cannot do:

• Disable any hardware component of your PC directly.

Despite the fact that viruses cannot currently exploit PC components deeper than operating systems, there is a non-zero chance that one day such viruses may still appear. They will know how to communicate directly with devices in order to put them into technological modes or change something directly in the firmware or settings. The most vulnerable link in this regard at the moment is your hard drive.

What viruses can do:

• Block access to the operating system or program
• Irreversibly modify, delete and encrypt your data
• Using social engineering methods to extract financial benefit from the user
• Monitor user actions: record passwords entered, resources visited, documents opened
• Transform infected operating system into a Botnet network participant who, on command, can create DDos attacks, send spam, and perform any other actions dictated by a special Botnet server
• Scan notebooks, documents, extracting mailing addresses from them, sending the latter to spammers or making your own mailings, inserting a virus into the body of the letter
• Disrupt the work of banking and other financial programs, obtain personal data from them, forward this data to attackers
• Reproduce through email, local network, Internet network, hard drives, flash media, any information media, through infected files, p2p clients, Online Games, instant messaging services (ICQ, MSN, Yahoo!), VoIP programs (Skype), etc.
• Download new viruses, turning your computer into a breeding ground for viruses
• Significantly slow down the operating system and programs
• Disable the operating system and programs

Problems caused by viruses can be very diverse: some can be eliminated, some cannot. Almost all of these difficulties can be avoided, or at least the likelihood of their occurrence can be minimized. To do this, it is enough to have a working antivirus with up-to-date databases on the system.

Alexey Gavrilenko

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