What are the dangers of computer viruses?

The harm of computer viruses is as follows: affecting the execution of programs and destroying user programs and data. A computer virus is a set of computer instructions or program codes that the programmer inserts into a computer program to destroy computer functions or data. It can affect the use of the computer and can replicate itself. Computer viruses can destroy user programs and data, making the program unable to execute.

Computer Virus is a code inserted into a computer program by the programmer that destroys computer functions or data. It can affect the use of the computer and can replicate itself. A set of computer instructions or program code.

Computer viruses are artificially created, destructive, contagious and latent programs that damage computer information or systems. It does not exist independently, but is hidden in other executable programs. When a computer is infected with a virus, it may affect the running speed of the machine at first, or crash and damage the system at worst. Therefore, the virus brings great losses to the user. Under normal circumstances, we call this destructive program a computer virus.

Computer viruses are contagious, covert, infectious, latent, excitable, expressive or destructive. The life cycle of a computer virus: development period → infection period → incubation period → attack period → discovery period → digestion period → extinction period.

Hazards

It is very important to enhance the awareness of computer virus prevention and realize the destructiveness and destructiveness of viruses. Nowadays, computers have been used in all walks of life, and computers and computer networks have become an important part of people's lives. Viruses can destroy and tamper with computer data, and theft can cause serious network security problems and affect the network. usage benefits.

(1) If a virus is activated, the computer will have a great reaction; most viruses will directly destroy the computer’s important information and data when activated. It will directly destroy the CMOS settings or delete important files and format them. Freezing the disk or rewriting the directory area will overwrite files with "junk" data. A computer virus is a piece of computer code that definitely occupies the computer's memory space. Some large viruses also replicate themselves inside the computer, causing a significant reduction in computer memory. When the virus is running, it also preempts interrupts, modifies the interrupt address, and adds virus information during the interrupt process. "Private goods" interfere with the normal operation of the system. After the virus invades the system, it will automatically collect important user data, steal and leak information and data, causing a large amount of user information to be leaked, causing immeasurable losses and serious consequences to users.

(2) Consume memory and disk space. For example, if you are not accessing the disk, but the disk indicator light is flashing wildly, or you find that the system has occupied a lot of memory when you are not actually running many programs, this may be a virus; many viruses are causing the problem. They are all resident in memory when active. Some file-type viruses can infect a large number of files in a short period of time, and each file is lengthened to varying degrees, causing a serious waste of disk space. Normal software often requires multiple tests by multiple people to be perfected, but computer viruses are usually quickly released by individuals after they are completed on a computer. Therefore, the harm that viruses bring to computers is not only what the manufacturer expected, but also Some are caused by computer virus errors.

(3) Computer viruses cause serious psychological pressure to users. The proliferation of viruses makes users fearful and always worried about being infected by viruses. Since most people do not know much about viruses, once there is a problem such as computer crash, software Abnormal operation and other phenomena, people often suspect that these phenomena may be caused by computer viruses. According to statistics, it is a common phenomenon for computer users to suspect that "the computer has a virus". More than 70% of computer users are worried that their computers have been invaded by viruses. In fact, not all computer phenomena are caused by viruses.

Classification of computer viruses

Computer viruses can be divided into three types: boot viruses, file viruses and hybrid viruses according to the classification of existing media; they are classified according to the link method It can be divided into three types: source code viruses, embedded viruses and operating system viruses. According to the system classification of computer virus attacks, it can be divided into viruses that attack DOS systems, viruses that attack Windows systems, and viruses that attack UNIX systems. Today's computer viruses are constantly introducing new ones, including some unique new viruses that cannot be classified according to conventional types for the time being, such as Internet viruses (which spread through the network, and some data carrying viruses are increasing), email viruses, etc. .

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