Types of computer viruses and protection against them
Hello again.
The topic of today's article. Kinds computer viruses, principles of their work, ways of infection with computer viruses.
What are computer viruses anyway.
A computer virus is a specially written program or assembly of algorithms that is written for the purpose of: making a joke, harming someone's computer, gaining access to your computer, intercepting passwords or extorting money. Viruses can self-copy and infect your programs and files, as well as boot sectors with malicious code.
Types of malware.
Malicious programs can be divided into two main types.
Viruses and worms.
Viruses- are distributed through a malicious file that you may have downloaded from the Internet, or may be on a pirated disc, or often transmitted via Skype under the guise of useful programs(I noticed that schoolchildren often come across the latter, they are allegedly given a mod for a game or cheats, but in fact it can turn out to be a virus that can harm).
The virus introduces its code to one of the programs, or is masked by a separate program in the place where users usually do not go (folders with the operating system, hidden system folders).
The virus cannot start itself unless you run the infected program yourself.
Worms already infect a lot of files on your computer, for example, all exe files, system files, boot sectors, etc.
Worms most often penetrate the system on their own, using vulnerabilities in your OS, your browser, or a certain program.
They can penetrate through chats, communication programs such as skype, icq, can be distributed via e-mail.
They can also be on sites, and using the vulnerability of your browser to penetrate your system.
Worms can spread over a local network, if one of the computers on the network becomes infected, it can spread to other computers, infecting all files on its way.
Worms try to write for the most popular programs. For example, now the most popular browser is Chrome, so scammers will try to write under it and make malicious code on sites under it. Because it is often more interesting to infect thousands of users who use a popular program than a hundred with an unpopular program. Although chrome is constantly improving protection.
The best protection against network worms th is to update your programs and your operating system. Many neglect updates, which they often regret.
A few years ago, I noticed the following worm.
But he obviously did not get through the Internet, but most likely through a pirated disk. The essence of his work was as follows - he created, as it were, a copy of each folder on a computer or on a flash drive. But in fact, he created not a similar folder, but an exe file. When you click on such an exe file, it spread even more throughout the system. And then you just got rid of it, you come to a friend with a flash drive, throw off music from him, and you return with a flash drive infected with such a worm and again you had to remove it. Whether this virus caused any other harm to the system, I do not know, but soon this virus ceased to exist.
The main types of viruses
In fact, there are many types and varieties of computer threats. And it's impossible to see everything. Therefore, we will consider the most common recent times and the most annoying.
Viruses are:
— File- located in an infected file, activated when the user turns on this program, they cannot be activated themselves.
— Boot- can be loaded when windows is loaded, hitting autoload, when inserting a USB flash drive or the like.
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macro viruses
- these are various scripts that may be on the site, they can be sent to you by mail or in Word and Excel documents, they perform certain functions embedded in the computer. Exploit vulnerabilities in your programs.
Types of viruses.
-Trojans
— Spies
- Ransomware
— Vandals
— Rootkits
— Botnet
— Keyloggers
These are the most basic types of threats that you may encounter. But in reality there are many more.
Some viruses can even be combined and contain several types of these threats at once.
- Trojans. The name comes from the Trojan horse. Penetrates into your computer under the guise of harmless programs, then it can open access to your computer or send your passwords to the owner.
Lately, Trojans called stealers have become widespread. They can steal saved passwords in your browser, in game mail clients. Immediately after launch, it copies your passwords and sends your passwords to an email or hosting to an attacker. It remains for him to collect your data, then they are either sold or used for their own purposes.
— Spies (spyware) track user actions. What sites the user visits or what the user does on their computer.
- Ransomware. These include Winlockers. The program completely or completely blocks access to the computer and requires money for unlocking, for example, put it on an account or so on. In no case should you send money if you fall for this. The computer will not be unlocked for you, and you will lose money. You have a direct road to the Drweb website, where you can find how to unlock many winlockers by entering a specific code or performing some actions. Some winlockers can disappear for example in a day.
— Vandals can block access to antivirus websites and access to antivirus and many other programs.
— Rootkits(rootkit) - hybrid viruses. They may contain various viruses. They can access your PC, and the person will have full access to your computer, and they can merge into the kernel level of your OS. Came from the world of Unix systems. They can mask various viruses, collect data about the computer and about all computer processes.
— Botnet quite a nasty thing. Botnets are huge networks of infected "zombie" computers that can be used to ddos websites and other cyber attacks using the infected computers. This type is very common and hard to detect, even antivirus companies may not know about their existence for a long time. A lot of people can be infected with them and not even suspect it. You are no exception, and maybe even me.
— Keyloggers(keylogger) - keyloggers. They intercept everything that you enter from the keyboard (websites, passwords) and send them to the owner.
Ways of infection with computer viruses.
main routes of infection.
— Vulnerability of the operating system.
— Vulnerability in the browser
- The quality of the antivirus is lame
— User Stupidity
- Removable media.
OS vulnerability- no matter how hard they try to rivet protection for the OS, security holes are found over time. Most viruses are written under windows as it is the most popular operating system. The best defense is to keep your operating system up to date and try to use the newest version.
Browsers- This happens due to browser vulnerabilities, especially if they are old again. It is also treated with frequent updates. There may also be problems if you download browser plugins from third-party resources.
Antivirus- free antiviruses that have less functionality, unlike paid ones. Although the paid ones do not give 100 results in defense and misfire. But it is desirable to have at least a free antivirus. I already wrote about free antiviruses in this article.
User Stupidity— clicks on banners, follow suspicious links from emails, etc., install software from suspicious places.
Removable media— viruses can be installed automatically from infected and specially prepared flash drives and other removable media. Not so long ago, the world heard about the BadUSB vulnerability.
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Types of infected objects.
Files- They infect your programs, system and regular files.
Boot sectors- resident viruses. They infect, as the name implies, the boot sectors of the computer, attribute their code to the startup of the computer and run when the operating system starts. Sometimes they are well disguised, which is difficult to remove from startup.
macros- Documents word, excel and the like. Using macros and vulnerabilities in Microsoft office tools introduces its own malicious code into your operating system.
Signs of a computer virus infection.
It is not a fact that the appearance of some of these signs means the presence of a virus in the system. But if they are, it is recommended to check your computer with an antivirus or contact a specialist.
One of the common symptoms is it's a heavy load on the computer. When your computer is running slowly, although you don’t seem to have anything turned on, programs that can heavily load your computer. But if you have an antivirus, note that antiviruses themselves load the computer very well. And in the absence of such software that can load, then more likely there are viruses. In general, I advise you to reduce the number of startup programs in autorun to begin with.
It can also be one of the signs of infection.
But not all viruses can heavily load the system, some are almost difficult to notice changes.
System errors. Drivers stop working, some programs start to work incorrectly or often crash with an error, but let's say this was not noticed before. Or programs start to reboot frequently. Of course, this happens due to antiviruses, for example, the antivirus deleted it by mistake, considering the system file to be malicious, or deleted the really infected file, but it was associated with the system files of the program and the removal caused such errors.
The appearance of ads in browsers or even banners start appearing on the desktop.
The appearance of non-standard sounds when the computer is running (squeak, clicks for no reason, and the like).
CD/DVD drive opens by itself, or just starts to read the disc, although the disc is not there.
Prolonged turning on or off of the computer.
Hijacking your passwords. If you notice that various spam is being sent on your behalf, from your mailbox or page social network, as the probability that the virus has penetrated your computer and transferred the passwords to the owner, if you notice this, I recommend checking with an antivirus in without fail(though not the fact that this is how the attacker got your password).
Frequent hard disk access. Every computer has an indicator that blinks when you use various programs or when you copy, download, move files. For example, your computer is just turned on but no programs are being used, but the indicator starts blinking frequently, supposedly programs are being used. These are already viruses at the hard disk level.
That's actually considered computer viruses that you can meet on the Internet. But in fact, there are many times more of them, and it is not possible to fully protect yourself, unless you do not use the Internet, do not buy disks, and do not turn on the computer at all.
The human species constantly interacts with wildlife. Today, the opinions of world scientists are unanimous - viruses appeared long before the formation of the DNA molecule. There is a hypothesis that the bacterium is the evolutionary result of degenerative unicellular organisms, a kind of descendant of an ancient pre-cellular life form. The annual struggle of mankind with unknown types of viruses leads to reasonable conclusions - they mutate, develop and adapt to the conditions we create, while actively participating in the evolutionary formation of the genetic material of all living organisms. Every year, massive pandemics claim hundreds human lives.
We present you the top 10 most dangerous viruses, known to man not only from ancient times.
Human Immunodeficiency Virus (AIDS)
The deadly virus rightfully takes first place in the world ranking. To date, there is no cure for AIDS. It is possible to protect yourself from infection only with the help of effective prevention.
The first cases of AIDS were recorded in the 1930s in one of the countries West Africa. Then it was believed that the carrier of the virus were monkeys. The official isolation and laboratory study of the pathogen was carried out in 1980 with the identification of 440 US carriers.
The causative agent, the human immunodeficiency virus, destroys the defense system by damaging CD4-lymphocytes (cells responsible for the destruction of pathogenic infection), a decrease in the number of which leads to a decrease in the body's resistance to the surrounding pathogenic microflora.
The source of infection is a latent carrier or a sick person. Infection occurs through blood and biological secretions - sexual contact of all kinds, blood transfusion, childbirth, breastfeeding, injections, organ transplants, household microtraumas.
Incubation period long, from the moment the pathogen enters the body to the onset of symptoms, a lot of time passes - from a year or more.
Average duration life of an HIV-infected person - no more than 11-15 years.
Known stages of HIV
Feverish - appears in 50% of those infected, is characterized by minor intestinal or cold symptoms (body aches, diarrhea, nausea, rarely a rash and sore throat);
asymptomatic - duration up to 10 years. The virus destroys the immune defense. Very rarely, small swellings appear in the area of the lymph nodes;
development of AIDS. Activation of latent pathogenic organisms living in the human body. Appearance white plaque on the tongue, hemorrhagic eruptions of the extremities, sweating, decreased vision, a sharp weight loss of up to 10% of the total mass. Then the condition is aggravated by hyperthermia, diarrhea, lymphoma, tuberculosis and Kaposi's sarcoma.
The life expectancy of an HIV patient with progressive symptoms is no more than two years.
HIV treatment is carried out with immunostimulating, antiviral and antibacterial drugs in stationary conditions. The main goal of drug therapy is to prolong the life of an infected person.
Fundamental Methods for Effective HIV Prevention
1. Use of a condom, one sexual partner.
2. Do not use other people's hygiene items.
3. For medical manipulations, the use of a disposable instrument.
Rabies virus
A very dangerous virus in the world for humans. The disease has been known since ancient times. effective method The fight against the disease is timely and urgent revaccination immediately after infection. The countries of Asia, Africa, Canada, the USA are most vulnerable to infection (the first cases of human infection since 1880).
The causative agent, the Rabies virus, is transmitted through a bite, ingestion of the saliva of a domestic or wild animal into the bloodstream. Having entered the body, the virus destroys the central nervous system, causing meningoencephalitis, asphyxia and cardiac arrest due to paralysis of the respiratory tract.
The source is an infected animal - a dog, a cat, a fox, a raccoon, rodents. Infection by a pet of a person is possible even during the incubation period.
The process of disease development lasts from 10 days to a year in humans (usually 1-4 months), animals - up to 2-3 weeks. If not vaccinated within the first 10 days after being bitten, there is a 99% chance of death in humans (only 3 cases of recovery after the active phase are known worldwide).
Symptoms of rabies
Symptoms of the progress of the disease are characterized by periods:
1. Early - subfebrile body temperature, anxiety (1-3 days).
2. Razgar - aggression, hallucinations, delirium, fear of water (up to 4 days).
3. Paralytic - the state of a living corpse, indifference, lack of reactions, paralysis of the limbs, suffocation (up to 8 days).
Treatment of the patient during the period of active symptoms is not effective - medical supervision is limited to symptomatic measures to alleviate the condition of the infected person.
Rabies preventive measures taken
Timely vaccination of pets;
seek immediate medical attention if bitten by stray dogs, cats or wild animals;
passage full course conservative therapy immediately after the bite.
Ebola virus (hemorrhagic fever)
This is the name of a dangerous, highly contagious virus for humans, the causative agent of which is the filovirus Zaire ebolavirus. First identified in 1976, during an epidemic in Zaire that engulfed most the Ebola River Basin (almost 90% of deaths).
It has been established that the carriers of the virus are rodents, bats and monkeys.
Subsequent epidemics are caused by mutational virion species:
Nzara town and Uganda (Sudan). In 1976, the death rate from this virus was 54%, in 1979 - 53%, in 2000 - 53% of cases. The source of infection has not been identified;
Philippines, then USA. 1989 - outbreak of hemorrhagic fever among monkeys;
Tai forest (Africa). 1994 - human infection through laboratory research corpses of monkeys;
Bundibugyo (Uganda). 2007 - the epidemic claimed 40 human lives out of 140 registered cases of the disease;
Congo. 2012 - 37% mortality.
Currently, the Ebola vaccine is being tested in monkeys, so there is no information about the next arrival of the antiserum on the consumer market. The Ministry of Health officially confirmed the admission of experimental serum to prevent the popularization of epidemics.
The disease is characterized by seasonal outbreaks and is recognized as a global threat to humanity.
Localization of the pathogen mainly in the blood, saliva, other secretions and fluids of the infected (sperm, urine, mucus). Transmitted by contact, injection, sexual contact. Infection is not excluded by shaking hands and using common household items.
The period of development of the disease covers 2-3 weeks. Once in the body, the virus blocks the complementary blood group (inactive proenzymes that bind to antigenic bodies to destroy and agglutinate the latter).
The main signs of Ebola fever are hemorrhagic rashes, fatigue, apathy, pain in the spine and extremities, pharyngitis, and a sharp increase in temperature. Then comes diarrhea, abdominal pain, disorientation. A week later, the active phase is replaced by increased pain, nosebleeds, bloody diarrhea, dry cough and acute pancreatitis. On the 14th day of illness - infectious intoxication, hemorrhagic shock, massive blood loss.
Plasma of convalescents (carriers who acquire immunity after illness) has a positive trend in the treatment of a patient with Ebola. However, the method does not guarantee a complete recovery. The total death rate from the Ebola virus is about 50%.
Marburg virus (hemorrhagic fever)
A close relative of Ebola hemorrhagic fever. 1967 is the date of the first human infection with this virus, recorded in Marburg (Germany). The source of infection was monkeys from Uganda, brought for experiments.
The causative agent of the disease is the Filoviridae virus of zoonotic origin (transmitted to humans from animals). It is assumed that infection occurs through contact with biological fluid (saliva, vomit, blood, secretions).
Risk group for potential Marburg virus infection
veterinarians in contact with monkeys from Africa;
scientists studying the virus;
healthcare workers in contact with a sick Marburg virus;
laboratory staff involved in the study of biomaterial.
The period of development of fever (incubation) lasts no more than 10 days. Then the patient feels fever, muscle pain. Gradually, the symptoms worsen - rashes appear on the body, diarrhea, abdominal pain, jaundice, pancreatitis, organic dysfunction, weight loss. Further development of liver failure, internal blood loss, delirium and hallucinations is not excluded. The mortality rate ranges from 25 to 85%.
There is no vaccine against Marburg virus.
The study of contagiousness and the development of serum began in 2014. Today, the world knows nanoparticles that have the ability of viral dereplication, tested on monkeys.
According to scientists, the only way protection against the virus - the use of maximum precautions when in contact with African animals.
Smallpox virus (natural)
The variola virus, which is dangerous to humans, is divided into two types: Variola Minor (chickenpox) and Magor (black pox). Epidemics of smallpox claim from 40% to 90% of human lives, the survivors become visually impaired.
The first mention of a deadly disease in the 4th century is an epidemic of smallpox in China (95% mortality). VI century - the disease affects densely populated areas of Korea (88% of deaths). 737 - Japan's population decline by 35% (pandemic of smallpox). Smallpox has claimed millions of European lives since the 1500s. Between 1700 and 1800, the first smallpox serum was made and tested. Variolation (grafting) had the effect of reducing mortality by up to 10%.
Infection occurs by airborne droplets, upon contact with a carrier or a patient. The incubation period does not exceed two weeks. Entering the lymph, the virus spreads through the epithelium, forming purulent pustules. Severe forms of the disease develop hemorrhagic syndrome, encephalitis, toxic shock and death. A cured person gets ugly scars from pustules all over the body. As a consequence of extensive hemorrhoidal hemorrhages, the survivors become blind.
A person is contagious to others from the last five days of incubation until the crusts of pustules fall off.
The body of a person who died of smallpox is contagious for up to four months.
Treatment of natural smallpox is carried out with antiseptic and bacterial preparations, broad-spectrum antibiotics.
Smallpox virus has been repeatedly used by mankind as biological weapons. To date, there is no data on the presence of the virus in the natural climate, samples are stored in the laboratory.
Spanish influenza (Spanish flu) or influenza virus
The most dangerous virus in the world. During the First World War, more than 35% of the world's population was infected with the Spanish flu, of which the mortality rate was about 5%. total strength(150 million people).
The causative agent is the H1N1 virus, isolated during the study of a mummy in Alaska (XVIII-XIX centuries). It is transmitted by airborne droplets. Through certain time incubation (up to 4 days), the patient develops cyanosis of the skin, a sharp increase in body temperature up to 40 degrees, coughing up blood. Then lightning-fast development of pulmonary hemorrhage. Death comes from choking on one's own blood.
The development of severe complications with a fatal outcome in the first days of the disease was observed mainly in patients with reduced immunity, during pregnancy, in children under 14 years of age, and in the elderly.
Signs of infection
Characteristic signs of infection for patients at risk
1. The rapid development of hemorrhagic pneumonia (in a few hours).
2. The disease affects only adults (from 25 to 45 years old).
3. The probability of death is 95% on the first day of the disease.
The massive Spanish flu pandemic during the First World War is recognized as a global catastrophe of a large-scale nature.
In subsequent years, active vaccination of the population was carried out, infected patients were treated with antiviral drugs.
To date, the H1N1 virus has been modified and has a milder course. When outbreaks of Spanish flu are detected, the lethal outcome is no more than 2% (mainly among patients who applied for medical help late).
Dengue virus (bone-breaking fever or date disease)
Secondary infection with the Dengue virus is more dangerous for a person than the primary one, since the body's production of antibodies and the acquisition of immunity only exacerbate the course of a recurrent disease.
A dangerous virus that is transmitted transmissibly (through the bites of blood-sucking insects). Places of localization - in the countries of the South and East Asia, Africa, Caribbean. The annual incidence is about 50 million people, with a hemorrhagic form, the death rate is up to 50%.
In the middle of the 20th century, the Flavivirus virion was isolated as the causative agent of the Dengue virus (the Flaviviridae family of abroviruses - antigenic group B).
The source of infection are monkeys, a sick patient, rarely bats. The disease is believed to be carried by mosquitoes. The insect is contagious for the first three months after the bite of an infected individual and can be a carrier of several virus serotypes at once. The period of development of the virus in the human body is up to seven days.
The main symptoms of the mild stage (primary infection - classic)
muscle and bone pain;
temperature increase up to 40 degrees;
heartbeat;
hyperemia of the eyeballs, throat;
rashes on the body, itching;
anxiety.
A more severe form of the disease develops in the local population, and occurs when a single infection with several varieties of abrovirus.
Symptoms of the hemorrhagic form of the disease
increased lymph, nausea, vomiting;
cough, weakness, abdominal pain;
development of pancreatitis, gastric bleeding;
cyanosis;
heart palpitations, vomiting blood.
Dengue fever is treated with painkillers and vitamins. In severe forms, plasma therapy, coagulants, glucocorticoids are used.
Zika virus (Zika fever)
One of the varieties of dangerous viruses transmitted transmissibly. Laboratory isolated from the monkeys of the Zeke forest (Uganda) in 1947. 
The first human infection was recorded in 1968 (Nigeria). From 1951 to 1982, serological cultures of the virus were found in India and Egypt. Since 2007, there has been an eastern popularization of the virus - New Caledonia, Easter and Cook Islands, South and Central America, Africa. In 2007, the disease was given pandemic status.
The causative agent is the Flavivirus virus, which causes the same type of disease. Monkeys are the source of infection. The infection is transmitted with the help of blood-sucking insects; transmission through blood, natural secretions, and sexual contact is also not excluded.
The incubation period lasts no more than two weeks. The first signs of the disease are rashes on the body, fever, aches, pain in the joints, swelling of the limbs. There are no signs of severe intoxication.
AT modern world So far, there are no specific drugs for the treatment of a viral infection. The disease is not fatal, but it has pronounced degree neurotropism (affects nerve and neural stem cells). As a complication, it causes microcephaly.
Lassa virus (Lassa fever)
The infection is characterized by a severe course respiratory organs, hemorrhagic consequences, and a high percentage lethal outcome.
The causative agent is the Lassa mammarenavirus virus, officially recognized as one of the most dangerous to humans. The source of infection are rats. The main localization is Western and Central Africa. The mechanism of transmission of the virus to humans is mainly fecal-oral (through food, water), aerosol and direct contact.
A patient with Lassa fever is very contagious to others. Infection from a person occurs through blood, natural secretions, in a contact manner. Cases of viral infection of medical staff through the instruments used are known.
The period of development of the disease lasts from six days to two to three weeks. The patient feels general malaise, fever, muscle pain. Gradually, there are lesions of the mucous eyes (conjunctivitis), an increase in lymph. In 80% of patients, manifestations of ulcerative necrotic pharyngitis of the throat are noted; fever is accompanied by diarrhea, vomiting. The second week of the disease is characterized by a rash, hemorrhagic bleeding (nasal, uterine, subcutaneous, pulmonary). A severe course is marked by swelling of the face and the rapid development of blood loss, general intoxication. Death is highly likely within 10-12 days of illness.
Treatment of patients with Lassa fever is carried out using antiviral drugs, antibiotics, and plasma administration is practiced in the early stages. In severe stages of the disease, mortality reaches 55%.
Protective preventive measures against infection with the Lassa virus include disinfection of premises, quarantine measures for those arriving from localization countries.
Rotavirus (intestinal flu)
Due to the presence of a 40% death rate, the disease caused is considered life-threatening. AT special group The risk of infection includes children under five years of age.
The causative agent of the disease is the Reoviridae virus isolated in 1943. Once in the body, it causes severe dehydration, followed by intoxication. The occurrence and development of the disease is seasonal - the virus is activated in the winter.
Focal cases of the disease are most often recorded in nursing homes and preschool institutions. The most famous outbreak of rotavirus infection was recorded in 2005 (Nicaragua - 30% mortality). According to studies, it is assumed that the focus of development of rotavirus arose due to a mutation of the virus. Previously, another outbreak of focal infection in Brazil (1977) is known.
The origin of the virus is not known. A person can become infected by drinking dirty water, through household appliances, or through close contact with an infected carrier. The period of development of symptoms of malaise is up to five days.
Symptoms of rotavirus infection
1. Primary - against the background of weakness and loss of strength, an increase in temperature to 40 degrees, vomiting, the appearance of a light yellow clay-like stool.
2. Secondary - signs of dehydration (fluid loss) are aggravated, against the background of vomiting and frequent liquid defecation, there is no appetite, a runny nose and sore throat, dark urine.
The treatment is carried out in a complex way - simultaneous relief of dehydration symptoms, reduction of intoxication of the body, intravenous fluid administration.
As a prophylactic against rotavirus infection, it is used in countries with insufficient levels of medical care and marked signs of unsanitary conditions.
The ranking of the top 10 dangerous viruses on the planet is not final. Which of them is the most dangerous is also impossible to predict. Every day, scientists discover new types of viruses, investigate their origin and nature, and try to understand how safe they are for human existence.
However, despite the high scientific achievements, the problem of human resistance to viruses remains relevant to this day. To save our population, it is necessary to constantly actively resist destructive viral diseases. Therefore, it is very important to know the etiology of the most aggressive, but already familiar to mankind, biological microorganisms.
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 different approaches to analysis must be applied. For example, there are pathogens that change the overall mortality rate of the population. Others lead to lethal outcome 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 viral disease one type or another.
Arboviruses of the Flaviviridae family
These dangerous pathogens cause a specific disease - dengue fever. The patient is worried sharp 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
In the modern world, the "common cold" does not cause people to panic, as it is easily treatable. Simply put, human immunity is resistant to many strains of respiratory infections. 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 into a 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. Despite the available methods of 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 high fever 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
It is considered the most dangerous virus that is transmitted through body fluids and blood. Most common causes HIV spread is unsterilized medical and cosmetic devices, drug addiction (reuse of syringes), promiscuity. The average life expectancy 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.
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, it needs a program to “stick” to it to work successfully.
Thus, we can say that a malicious program (Malware) is any program that has been created to provide access to a computer and 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.
In our life there are so many scary stories about evil spirits, ghosts, brownies. But unlike these tales, which still have no evidence, there are really terrible and inexplicable things in the world - mysterious viruses. What is a virus anyway? This is a microscopically small, pathogenic microorganism, which for the most part does not have a cellular structure.
In this article, we will look at the 10 most mysterious viruses on the planet.
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10black widow virus
Recently, scientists have made a unique discovery. The WO virus, which infects bacteria (bacteriophage), has appropriated the Black Widow spider's venom gene. Previously, it was believed that bacteriophages do not exchange genes with animals, but recently American scientists informed the world that this bacteriophage is able to take pieces of other genes, combining them together, thereby forming a new gene. This is very unique phenomenon, which scientists recently discovered.
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9
Infertility is the inability of a man and woman to conceive a child with regular sexual activity.
Infertility is divided into two categories - absolute and relative. In women, it can be primary (when pregnancy never occurred) and secondary (pregnancy was, even if it ended in miscarriage or ectopic pregnancy).
Italian scientists conducted research and concluded that one of the causes of infertility may be the HHV-6A virus, one of the herpes viruses. It causes immune responses that prevent the fetus from attaching to the uterine wall. Treatment is with antiviral therapy and injections of the hormone estradiol.
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8
Scientists have discovered an incredibly tenacious microbe in the SIRV2 virus. He is able to survive even in boiling acid. Survives even at a temperature of 175 degrees Celsius. It is also resistant to UV radiation. Scientists have found striking similarities between SIRV2 and bacterial spores from diseases that are difficult to treat, such as anthrax. They intend to study the virus in more detail in order to further use it for gene therapy.
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7Multicomponent virus
This virus is very unusual, because the usual virus is one, and this one is divided into five parts. To become infected, a cell must be exposed to at least four genes.
The virus was found in the genes of a mosquito, that is, a person needs at least 4 mosquito bites to become infected with the disease. This study was part of a larger project to find out what viruses mosquitoes could carry, but made such an unexpected discovery.
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6
8% of the human genome comes from ancient viruses. Retroviruses target human sperm and eggs in order to further gain a foothold in the DNA of a new person and be transmitted from generation to generation. Despite the fact that millions of years have passed, the virus may reappear. Exact time Researchers do not know awakening - this can happen both during the appearance of new diseases and as a result of the work of a viral cell that is attached to the DNA of our body.
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5
In the summer of 2014, a resident of Bourbon County was bitten by a tick. He went to the hospital complaining of vomiting, rash and high temperature. He developed a lung kidney failure On the 11th day he died. A new virus was isolated from his blood and attributed to the Thogotovirus species, among which are the causative agents of meningitis and encephalitis that affect the membranes of the brain. But unlike them, the bourbon virus infects white blood cells. To date, this is the only case of infection with the bourbon virus.
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4
french research group discovered a virus in the Siberian permafrost, which is already 30,000 years old! But there is nothing to be afraid of - the virus is not capable of infecting animal or human cells. He hit single-celled amoebas during Upper Paleolithic or Neolithic. The Siberian virus is wider in diameter than other giants. It has a genome of 600,000 base pairs that can make 500 proteins.
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3
These viruses are responsible for the death of most prokaryotes in the deep ocean, scientists say. As in the entire biosphere of the planet, in the deep ocean, viruses are the most common biological creatures. A partial genetic match has been found between the waters of California and Norway.
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2Mysterious paralysis
In the United States in 2015, more than a hundred cases of mysterious paralysis in children were recorded. The symptoms started like a common cold. At first, scientists suspected the EV-D68 virus, as it can cause paralysis, but it was found in only 20% of cases. The researchers said enterovirus D68, and now enterovirus C105, were found in respiratory tract children, but were not found in the cerebrospinal fluid. The cause of the mysterious paralysis outbreak is still a mystery.
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1
This is an acute febrile disease that affects blood vessels and leads to the development of thrombohemorrhagic syndrome. Last year, 129 people died from an unknown disease, but it is not yet clear if they were carriers of the same disease.
Many viruses were found in the blood samples of the dead. Most scientists believe that ticks or mosquitoes carry the disease, but do not exclude that the virus enters the body with bacteria. It is still unknown whether the fever is transmitted from person to person.
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Conclusion
It was an article about the strangest and most mysterious viruses on the planet. Thank you for your attention!