Computer viruses. Types, types, ways of infection. Types of viruses. What viruses do humans have

21.10.2019

Of all the organisms that exist on the planet, pathogens have the largest coverage area and abundance, including bacteria, bacilli and, of course, viruses invisible to the human eye. The latter are the causative agents of diseases that differ in symptoms, nature of the course and severity.

It is quite difficult to identify the most dangerous virus for humans, since they must be applied different approaches to the analysis. For example, there are pathogens that change the overall mortality rate of the population. Others lead to the death of already infected people. Still others kill the owner faster than he manages to distribute them to other people. For example, with a mortality rate of up to 3%, the Ebola virus and the Spanish flu pandemic have killed more than 100 million people. And there is also a historical approach to assessing the harmfulness of the virus. It demonstrates which microorganism has killed the most people throughout human history.

We offer you a list of the 10 most dangerous viruses on the planet that annually claim hundreds and thousands of human lives. Let's add some statistics and numbers, as well as data on characteristic symptoms for a viral disease of one type or another.

Arboviruses of the Flaviviridae family

These dangerous pathogens cause a specific disease - dengue fever. The patient is concerned about acute pain in the musculoskeletal system (joints, especially knees, spine). The patient also notes hyperthermia, severe fever and fever, nausea and vomiting. Often there is an itchy rash on the body. It is known that if the disease progresses to severe form, then in half of the cases ends in death. You can pick up an arbovirus through an insect bite (tick, mosquito, etc.). Before traveling to the area of the spread of the virus, take care of preventive vaccinations and other personal protection methods.

flu virus

AT modern world The "common cold" does not cause panic in people, as it is easily treatable. Simply put, human immunity is resistant to many strains of infection. respiratory tract. But few people know that there are more than 2 thousand variants of the virus in the world, which are classified according to serotypes (B, A, C) and strains. Serotype A is life-threatening, as it causes massive epidemics and even pandemics. Every year, up to half a million people die from a seasonal flu outbreak (most often preschoolers and the elderly). The virulent strain of the virus caused the so-called "Spanish flu", which in 1918 struck about a third of the world's population, killing about 100 million patients. At the same time, people with strong immunity were most at risk, which eventually provoked the so-called “cytokine storm”.

Hepatitis C virus (HCV)

A specific disease can be masked by symptoms under other pathologies, so a person can long time be unaware of the presence of a virus in the body. So the disease gradually becomes chronic, which provokes liver failure and, as often happens, death. The virus takes about 350 thousand patients annually, and in developing countries. Relentless statistics says that there are 200 million carriers of this dangerous microorganism in the world. Unfortunately, the disease is not treatable, and an effective vaccine has not been developed. Infection with hepatitis C occurs through the blood, and the source is often medical and cosmetic instruments, unprotected sexual intercourse, and poor hygiene.

Hepatitis B virus (HBV)

This hepatitis virus leaves the patient a chance for recovery, but in 20-30% of cases it still progresses to chronic form causing cirrhosis or liver cancer. In a year, the "reaper" claims about 700 thousand human lives. Also, like the previous type of hepatitis virus, it provokes an asymptomatic disease that slowly attacks the liver for years. Most often, the disease is diagnosed in children. Carriers of the virus may not suffer the consequences, but actively transmit it to others. The virus is characterized by resistance to temperature fluctuations. It is transmitted through blood drops in the household way, as well as through injections, tools, sharp instruments, sexual intercourse.

Rabies virus

Occurs in warm-blooded animals and is transmitted from them to humans. Causes rapid and irreversible damage to the central nervous system. The virus is transmitted through the saliva of an infected animal during a bite. The temperature rises to subfebrile levels, the patient complains of sleep disturbances, attacks of aggression and hallucinations, paranoid delusions. Following is paralysis of the limbs and eye muscles, the respiratory system, which leads to death. Unfortunately, the symptoms of the disease appear already at the stage when the virus enters the brain and causes degradation. nerve cells. Only a vaccine given as soon as possible after being bitten by a stray animal can save a life.

Rotavirus

It is a group of viruses that is transmitted by the fecal-oral route. Causes attacks of acute diarrhea, dehydration and is observed mainly in young children. In spite of available methods therapy, the disease takes away annually about 450 thousand preschoolers (mostly residents of underdeveloped countries). Rotavirus is a disease dirty hands”, so the best prevention is personal hygiene, especially after visiting public places.

Ebola virus

The microorganism causes hemorrhagic fever. It is transmitted through body fluids, infected tissues and blood. Accompanied by a sharp increase in temperature, muscle aches, lethargy, muscle cramps, migraine and sore throat. Nausea and vomiting, indigestion, skin rashes, kidney and liver dysfunction can also be observed. In severe form, external and internal hemorrhages are noted. The death rate from Ebola in 2015 was 42% of cases.

Variola virus

Surviving patients can be seen from afar - the skin is dotted with numerous scars. The first symptoms of "black pox" are heat and a rash on the body (purulent blisters). With complications, headaches, vertigo, pain in the sacro-lumbar region, nausea and vomiting are noted. In the 20th century, the epidemic took about 300-500 million lives. The last case was registered in 1977. climate change in last years may lead to the return of the disease. By the way, the smallpox virus only infects humans.

Virus of the Flaviviridae family

The pathogen is carried by mosquitoes living in areas South America and on African continent. Once in the body, the virus causes "yellow fever", which is accompanied by jaundice. Since the 1980s, the spread of the disease has been increasing, which is explained by the deterioration of immunity in people and climate change. In a severe form of the disease, the liver cannot cope with the function and death occurs. Tourists visiting the above countries are advised to get vaccinated.

AIDS virus

Considered the most dangerous virus, which is transmitted through body fluids and blood. Most common causes HIV spread is unsterilized medical and cosmetic devices, drug addiction (reuse of syringes), promiscuity. Average duration the life of an infected person without adequate therapy is 9-11 years.

These dangerous microorganisms are constantly next to us and threaten life. To prevent infection, get vaccinated in a timely manner, follow the rules of personal hygiene, use barrier methods of protection and avoid contact with infected people.

They lived on our planet long before us ... Viruses are very different - some of them lead to a banal flu, others to. Here we will talk about the latter. What viruses are currently considered?

1 Ebola virus

He stirred up the entire globe, reminding people that in some cases medicine also makes a helpless gesture. Appeared in Africa and advanced at an alarming pace to Europe and America. Given globalization and the absence of borders and customs for viruses, the possibility remains that this killing hemorrhagic fever will also be in our territory. There are many ways and means of spread, the most repeated is infection from a sick person through his blood.

2 Rabies virus

Rabies is different in that it can affect both people and animals, in particular dogs, cats, wild animals (wolf, fox, hedgehog), less often birds. The virus enters the blood and provokes severe damage to the nervous system; rabies vaccine required. Once symptoms appear in a person, the disease is incurable.

3 Human immunodeficiency virus

The human immunodeficiency virus, the plague of the 21st century, causes AIDS (acquired immunodeficiency syndrome), in which the work of the whole organism is undermined, and the most. Since the first case was registered (early 1990s), more than 25 million people have died of AIDS. There is no vaccine for it, and now the search for a vaccine against HIV is one of the most pressing issues.

4 Variola virus

It is called Variola and has 2 varieties: Minor - leads to death in 1-3% of cases - and Major - death, according to some reports, occurs in 90% of cases (wow, "major" ...). Despite the fact that cases of smallpox are mentioned in the ancient Egyptian papyrus of Amenophis I, written 4 thousand years BC, however, the cause of this terrible disease, which deprives people, if not of life, then of sight, was established only at the beginning of the 20th century. , and only in the 70s did humanity manage to “pacify” the smallpox virus.

5 Influenza virus

It has three genera A, B and C and strains H1, H2, H3, as well as N1 and N2. Infection occurs by airborne droplets, so it often develops into a pandemic. An example of this is the Spanish flu, from which more than 50 million people died, as well as recently walking on our land bird flu which has been defused. Despite the huge number of drugs, the most reliable means of preventing the disease is vaccination. All ages are susceptible to the flu, so stay away from sneezing and coughing fellow citizens.

6 Hepatitis B virus (HBV)

Causes type B hepatitis, the most common infection liver in the world. In 20-30% of cases, it leads to cirrhosis and liver cancer, and can also develop into a chronic form. In some parts of Asia, 10% of the population are carriers of chronic hepatitis B.

7 Hepatitis C virus (HCV)

Causes a severe form of hepatitis. Hepatitis C is called the "gentle killer": it is asymptomatic (most infected people feel great for many years), flowing into a chronic form in 70-80% of cases. There is no cure or vaccine for it.

8 Virus of the Flaviviridae family

It causes yellow fever, an acute viral disease that can be contracted from a mosquito bite in the tropics and subtropics of Africa and South America. It is called "yellow" because of the jaundice that develops in many patients. This disease in half of the cases ends in death. Since the 80s 20th century the incidence of yellow fever began to increase again, and there are a lot of reasons for this: a decrease in the immunity of people, climate change, urbanization, and even deforestation.

9 Arboviruses of the family Flaviviridae

They cause diseases such as dengue fever. Its second name - bone breaking fever - this disease received for its symptoms: pain in the spine and joints, especially the knees. Also accompanied by chills elevated temperature body, nausea, redness of the face and eyes, rash. It has 2 forms of the disease, with a more severe - hemorrhagic - death occurs in 50% of cases.

10 Rotavirus

Causes the so-called rotavirus gastroenteritis, or "stomach flu" - an acute intestinal infection. The main danger is severe dehydration. Modern medicine has learned to cope with this disease, but in countries where there is no adequate medical treatment, rotavirus poses a serious threat: it claims 61,000 lives every year.
Scary? And yet there is already a precedent for curing a person from the Ebola virus, and work on an HIV vaccine does not stand still.

They are completely dependent on cells (bacteria, plant or animal) for reproduction. Viruses have a protein outer shell, and sometimes a lipid, and a DNA or RNA core. For infection to occur, the virus first attaches to a host cell. The viral DNA or RNA then enters the host cell and separates from the outer shell (virus cocapsulation) and replicates to the host cell with the participation of certain enzymes. Most RNA viruses copy their nucleic acid in the cytoplasm, while most DNA viruses copy it in the nucleus. The host cell usually dies, releasing new viruses that infect other host cells.

The consequences of viral infection vary greatly. Many infections cause acute illness after a short incubation period, and some are asymptomatic or cause minor symptoms that cannot be recognized except in retrospect. With many viral infections, under the influence of the body's defenses, recovery occurs, but some pass into a latent form. At latent infection viral RNA or DNA remains in host cells without causing disease for a long time, sometimes for years. Most often, human-to-human infection occurs during the asymptomatic period with latent, latent forms of viral infections. Various triggers can cause the process to reactivate, especially with immunosuppression.

Common viruses that remain latent are as follows

Herpesviruses.
Papovaviruses.

Some diseases are caused by viral reactivation in the CNS after a very long latent period. These diseases include progressive multifocal leukodystrophy (poliomavirus K), subacute sclerosing panencephalitis (measles virus), and progressive rubella panencephalitis (rubella virus). Spastic pseudosclerosis and bovine spongiform encephalopathy were previously classified as slow viral diseases due to prolonged incubation periods(years), but now known to be caused by prions; Prions are proteinaceous pathogens that are not bacteria, fungi or viruses and do not contain genetic material.

Several hundred different viruses can infect humans. Such viruses are often spread through respiratory and intestinal secretions. Some are transmitted sexually and through blood transfusion. Some viruses are transmitted by arthropod vectors. Viruses are distributed throughout the world, but their pathogenicity is limited by innate resistance, resistance, post-vaccination immunity, sanitary and other methods of control by the public health system, and prophylactic antiviral drugs.

Zoonotic viruses realize their biological cycles mainly in animals; humans are secondary or accidental hosts. These viruses exist in a certain environment, which is able to maintain their natural cycles, different from humans (vertebrates, arthropods, or both).

Viruses and cancer. Some viruses are oncogenic and predispose to certain cancers:

Papillomavirus: cervical and anal carcinoma.
Human T-lymphotropic virus 1: certain types of human leukemia and lymphoma.
Epstein-Barr virus: nasopharyngeal carcinoma, Burkitt's lymphoma, Hodgkin's lymphoma, and lymphomas in immunocompromised organ transplant recipients.
Hepatitis B and C viruses: hepatocellular carcinoma.
Human herpesvirus 8: Kaposi's sarcoma, primary lymphomas, and multicentric Castleman's disease (lymphoproliferative disease).

Types of viral diseases

Classifying viral infections according to the organ system involved (eg, lungs, gastrointestinal tract, skin, liver, CNS, mucosal membranes) may be clinically useful, although certain viral diseases (eg, mumps) are difficult to classify.

Respiratory infections. The most common viral infections are probably ARI. Respiratory infections are more likely to cause severe symptoms in infants, the elderly, and patients with lung or heart problems.

Gastrointestinal infections. afflicted age group primarily depends on the virus:

Rotavirus: children.
Norovirus: older children and adults.
Astrovirus: Usually infants and young children.
Adenovirus 40 and 41: infants.
Coronavirus-like pathogens: infants.

Local epidemics can be observed in children, especially during the colder season.

The main symptoms are vomiting and diarrhea.

The rotavirus vaccine, which is effective against most pathogenic strains, is part of the recommended vaccination schedule for toddlers. Hand washing and compliance sanitary regulations can help prevent spread.

Exanthematous infections. Some viruses cause only skin lesions (as in molluscum contagiosum and warts); others may cause systemic manifestations or skin lesions in various areas of the body surface. Transmission usually occurs from person to person; vector of alpha viruses - mosquito.

liver infections. At least 5 specific viruses (hepatitis A, B, C, D, and E) can cause hepatitis; everyone calls certain type hepatitis A. The hepatitis D virus can only infect if you have hepatitis B.

Other viruses can also infect the liver. Common examples are cytomegalovirus, Epstein-Barr virus, and yellow fever virus. Less common examples are echovirus, coxavirus, and herpes simplex, measles, rubella, and varicella viruses.

neurological infections. Most cases of encephalitis are caused by viruses. Many of these viruses are transmitted to humans by the bites of arthropods, mainly mosquitoes and ticks, which feed on blood; these viruses are called arboviruses. For such infections, prevention includes avoiding mosquito (mosquito) and tick bites.

Hemorrhagic fever. Certain viruses cause fever and a tendency to bleed and bleed. Spread by mosquitoes, ticks, or contact with infected animals (e.g. rodents, monkeys, the bats) and people.

Infections of the skin or mucous membranes. Some viruses cause skin or mucosal lesions that recur and may become chronic. Skin and mucous membrane infections are the most common type of herpes simplex viral infection. The human papillomavirus causes warts. Transmission by person-to-person contact.

Diseases with multiple lesions of various systems and organs. Enteroviruses, which include coxsackieviruses and echoviruses, can cause various multisystem syndromes, as can cytomegaloviruses.

Nonspecific febrile illness. Some viruses cause non-specific symptoms including fever, malaise, headaches, and myalgia. Transmission usually occurs through insects or arthropods.

Rift Valley fever rarely progresses to eye involvement, meningoencephalitis, or the hemorrhagic form (which has a 50% mortality rate).

Virus Diagnostics

Some viral diseases can be diagnosed clinically by well-known symptoms and syndromes (such as measles, rubella, roseola infantum, erythema infectiosum, and varicella) or epidemiologically during epidemic outbreaks (such as influenza). A clear laboratory diagnosis is needed mainly when a specific treatment may be helpful or when the pathogen may be a threat to public health (eg HIV). Typical laboratories in hospitals can test for individual viruses, but with relatively rare diseases(e.g., rabies, Eastern equine encephalitis), materials should be sent to government medical laboratories or the Centers for Disease Control and Prevention.

Serology in the acute and convalescent phases is sensitive and specific, but slow; a faster diagnosis can sometimes be made using culture methods, PCR, and sometimes histochemical methods using electron microscopy to determine viral antigens.

Virus treatment

Antivirals. Progress in the use of antivirals is rapid. Antiviral chemotherapy can target different phases of viral replication: interfering with the attachment of a virus particle to host cell membranes or decapsulation nucleic acids virus, inhibit a cellular receptor or factor necessary for viral replication, block specific virus-encoded enzymes and proteins that are produced in host cells and that are important for viral replication, and not for the normal metabolism of the host cell.

Antivirals are most commonly used therapeutically or prophylactically against herpesviruses (including cytomegalovirus), respiratory viruses, and HIV. However, some drugs are effective for various types viruses.

Interferons. Interferons are substances produced by infected host cells in response to viral or other foreign antigens. There are many different interferons that have numerous

effects such as blocking translation and transcription of viral RNA and arresting viral replication without disrupting the normal function of the host cell. Sometimes interferons are attached to polyethylene glycol (pegylated compounds), which gives a slow and prolonged release of interferon.

Viral diseases that can be treated with interferon:

Chronic hepatitis B and C.
Pointed condyloma.
Hairy cell leukemia.
Kaposi's sarcoma.

Depression and, at high doses, bone marrow suppression are also possible.

Virus Prevention

Vaccines. Vaccines work by stimulating innate immunity. Vaccines used include hepatitis A, hepatitis B, human papillomavirus, influenza, measles, mumps, polio, rabies, rotavirus, rubella, varicella and yellow fever. vaccines against adenovirus and smallpox are available but are only used in risk groups (eg army recruits).

Immunoglobulins. Immunoglobulins are available for passive immunization in selected situations. They can be used at risk of infection (eg hepatitis A), after exposure (eg rabies or hepatitis), and to treat an illness (eg vaccine eczema).

Preventive measures. Many viral infections can be prevented with common preventive measures(which vary depending on the mode of transmission of the pathogen). Washing hands, preparing food and water properly, avoiding contact with sick people, and practicing safe sex are important. With regard to infections that are carried by insects (eg mosquitoes, ticks), it is important to protect yourself from contact with them.

13.03.2011

creeper

The time of appearance of the first viruses is usually considered the beginning of the 1970s. It was then that the Creeper program appeared, written by BBN employee (Bolt Beranek and Newman) Bob Thomas. Creeper had the ability to self-move between servers. Once on the computer, she displayed the message "I" M THE CREEPER ... CATCH ME IF YOU CAN "(" I'm a Creeper ... Catch me if you can "). At its core, this program was not yet a full-fledged computer Creeper did not perform any destructive or espionage activities.Later, another BBN employee, Ray Tomlinson, wrote the Reaper program, which also roamed the network on its own and, when Creeper was detected, terminated its action.

Elk Cloner

More similar to a modern virus was the Elk Cloner program, identified in 1982. It spread by infecting the DOS operating system for the Apple II stored on floppy disks. When an uninfected floppy disk was found, the virus copied itself there. With every 50th boot, the virus showed a small comic poem. Although this virus was not intended to cause harm, it could corrupt the boot code on floppy disks with other systems. The author of this virus is a 15-year-old schoolboy from Pittsburgh Rich Skrenta (Rich Skrenta). Initially, the victims of this computer virus were the author's friends and acquaintances, as well as his mathematics teacher.

brain

The first viral epidemic was registered in 1987. It was caused by the Brain virus. It is the first computer virus created for IBM PC-compatible PCs. Its development was based solely on good intentions. It was released by two brothers who own a software development company. Thus, they wanted to punish local pirates who steal their software. However, the virus has created an entire epidemic, infecting more than 18,000 computers in the US alone. It is worth noting that the Brain virus was the first virus to use stealth technology to hide its presence in the system. When trying to read an infected sector, it “substituted” its uninfected original as well.

Jerusalem

The next significant event in the history of the development of viruses was the emergence of the Jerusalem virus. This virus was created in 1988 in Israel - hence its main name. The second name of the virus is Friday the 13th. It really activated only on Friday the 13th and deleted absolutely all data from hard drive. In those days, few people were familiar with computer viruses. It is natural that antivirus programs did not exist at all and users' computers were completely defenseless against malware. Therefore, such a destructive activity of this computer virus caused a tremendous panic.

Morris Worm

Also in 1988, we note the appearance of a virus under the name "Morris worm". It was the most terrible computer virus known at that time. This network worm was one of the first programs known to exploit buffer overflows. He managed to do the impossible - to disable the entire global network. True, it is worth noting that the network was not yet so global at that time. The failure, although it did not last at all for a long time, but the losses from it were estimated at $96 million. Its creator was a graduate student of the faculty Computing Cornell University Robert T. Morris. The case went to court, where Robert Morris faced up to five years in prison and a $250,000 fine, however, taking into account extenuating circumstances, the court sentenced him to three years probation, a $10,000 fine, and 400 hours of community service.

Michelangelo ("March6")

Was discovered in 1992. He spawned a wave of publications in the Western media. This virus was expected to damage information on millions of computers. Although it has been greatly overestimated, it is still deservedly considered one of the most ruthless computer viruses. Using floppy disks, he penetrated the boot sector of the disk, quietly sat there, not reminding of his existence until March 6th. And on March 6, I successfully erased all data from the hard drive. This virus greatly enriched the companies that produce anti-virus software. They managed to create mass hysteria and provoke purchases of anti-virus software, while only about 10,000 machines were affected by this computer virus.

Chernobyl (CIH)

One of the most famous viruses, which has become the most destructive in all previous years. Created in 1998 by a Taiwanese student. The initials of this student are in the name of the virus. The virus entered the user's computer and remained inactive there until April 26. This computer virus destroyed the information on the hard drive and overwrote the Flash BIOS. In some cases, this led to the replacement of the microcircuit, or even to the replacement of the motherboard. The Chernobyl virus epidemic occurred in 1999. Then more than 300 thousand computers were put out of action. Also, the virus continued to harm computers around the world in subsequent years.

Melissa

On March 26, 1999, the first worldwide known mail worm was released. The worm infected MS Word files and sent copies of itself in MS Outlook messages. The virus spread with great speed. The amount of damage caused is estimated at more than $100 million.

ILOVEYOU ("Letter of Happiness")

Appeared in 2000. A letter came to the mail with the subject "I LOVE YOU" to which the file was attached. By downloading the attachment, the user infected his computer. The virus sent an incredible amount of emails from the hapless user's computer. He also deleted important files on the computer. By some estimates, it cost PC users around the world more than $10 billion. The ILOVEYOU virus infected 10% of all computers that existed at that time. Agree, quite shocking figures.

Nimda

The name of this computer virus is the word "admin" spelled backwards. This virus appeared in 2001. Once on the computer, the virus immediately assigned itself administrator rights and began its destructive activity. It changed and violated the design of sites, blocked access to hosts, IP addresses, etc. To spread the virus used several various ways. He did this so effectively that within 22 minutes after his launch into the network he became the most common computer virus on the Internet.

Sasser

In 2004, this worm made a lot of noise. Home computers and small businesses have been hardest hit by the virus, although some large companies have also experienced serious problems. In the German postal service alone, up to 300,000 terminals were infected, which prevented employees from dispensing cash to customers. The computers of the investment bank Goldman Sachs, the European Commission, and 19 regional offices of the British Coast Guard also became victims of the worm. In one of the terminals of London's Hithrow airport, British Airways failed half of all computers at check-in counters, and in the US city of New Orleans, up to 500 hospitals were closed within a few hours. Social and health institutions in Washington were also affected.

To become infected with this worm, it was enough just to connect your computer to the Internet and wait a few minutes. The worm penetrated a computer, scanned the Internet for other computers with an open hole, and sent a virus to them. The virus did not cause any particular harm - it simply rebooted the computer. A special FBI cybersecurity agency joined in the search for the worm. The main victim, Microsoft Corporation, set a price of $ 250,000 for the attacker. And he turned out to be ... a student high school Sven Jaschan from the German city of Rottenburg. As some observers believe, the teenager created Sasser not only to become famous, but also out of filial love - to improve things. small company PC-Help for maintenance of a PC owned by his mother.

My Doom

This worm was launched in January 2004. At that moment, it becomes the fastest worm that spreads across e-mail. Each subsequent infected computer sent more spam than the previous one. In addition, he changed the operating system, blocking access to the websites of anti-virus companies, the Microsoft website, and news feeds. This virus even attempted a DDOS attack on the Microsoft website. At the same time, the whole multitude of infected computers brought down a huge number of requests from different parts of the world to the Microsoft website. The server devotes all its resources to processing these requests and becomes almost inaccessible to ordinary users. Users of attacked computers may not even be aware that their machine is being used by hackers.

Conficker

First appeared online in 2008. One of the most dangerous computer worms today. This virus attacks operating systems of the Microsoft Windows family. The worm finds Windows buffer overflow vulnerabilities and executes code using a fake RPC request. As of January 2009, the virus infected 12 million computers worldwide. The virus has taken such a toll Microsoft company promised 250,000 dollars for information about the creators of the virus.

This list, as you know, is not complete. New viruses are released every day, and there is no guarantee that the next one will not cause another epidemic. Installing a licensed antivirus from a reputable antivirus software manufacturer on a licensed operating system with latest updates will help keep your computer as secure as possible. In addition, there are certain precautions when working on a computer from infection with computer viruses, which we will discuss in our next articles.

Most the best choice antiviruses in Ukraine in the online store of licensed programs OnlySoft:

Computer viruses- special programs that are created by attackers to obtain any benefit. The principle of their operation can be different: they either steal information or encourage the user to perform some actions for the benefit of attackers, for example, replenish an account or send money.
Today there are many different viruses. The main ones will be discussed in this article.

Worm is a malicious program whose purpose is to fill the computer with all sorts of garbage so that it becomes slow and clumsy. The worm is able to reproduce itself, but cannot be part of the program. Most often, infection with this virus occurs through emails.

Trojan (Trojan, Trojan horse)- This program fully justifies its name. It infiltrates other programs and hides there until the host program is launched. Until the host program is launched, the virus cannot cause harm. Most often, a Trojan horse is used to delete, modify, or steal data. Trojans cannot reproduce on their own.

Spyware- these Stirlitz collect information about the user and his actions. Most often, they steal confidential information: passwords, addresses, card/account numbers, etc.
Zombies - this name was given to malicious programs because they actually make a "limp" machine out of a computer, obeying intruders. Simply put, bad people can control someone's computer with these malware. Most often, the user does not even know that his computer is no longer only his.

Blocker program (banner)- these programs block access to the operating system. When the computer is turned on, the user sees a pop-up window in which they are usually accused of something: copyright infringement or downloading pirated software. Further, there are threats of complete removal of all information from the computer. In order to avoid this, the user must replenish the account of a certain phone or send SMS. Only now, even if the user does all these operations, the threat banner will not go anywhere.

Boot viruses- hit the boot sector of the hard drive (hard disk). Their goal is to significantly slow down the process of loading the operating system. After a long exposure to these viruses on the computer, there is a high probability that the operating system will not load at all.

Exploit- These are special programs that are used by attackers to penetrate the operating system through its vulnerabilities, unprotected places. They are used to infiltrate programs that steal information necessary to obtain access rights to a computer.

Phishing- this is the name of the action when the attacker sends emails to his victims. The letters usually contain a request for confirmation of personal data: full name, passwords, PIN codes, etc. Thus, a hacker can impersonate another person and, for example, withdraw all the money from his account.

Spyware- programs that send user data to third parties without his knowledge. Spies are engaged in the fact that they study the behavior of the user and his favorite places on the Internet, and then show ads that will definitely be of interest to him.

rootkit – software, which allow an attacker to freely penetrate the victim's software, and then completely hide all traces of their presence.
Polymorphic viruses are viruses that camouflage and reincarnate. While working, they can change their own code. And therefore they are very difficult to detect.

Software virus- a program that attaches itself to other programs and disrupts their work. Unlike a Trojan, a computer virus can replicate and, unlike a worm, successful work he needs a program to which he can "stick".
Thus, we can say that a malicious program (Malware) is any program that was created to provide access to a computer and the information stored in it without the permission of the owner of this computer itself. The purpose of such actions is to harm or steal any information. The term " Malware” is generalized for all existing viruses. It is worth remembering that a program that has been infected with a virus will no longer work correctly. Therefore, it must be removed and then reinstalled.