The basic concept of computer viruses and their characteristics

Main features 1, the reproduction of computer viruses can be like biological viruses to reproduce, when the normal program runs, it also runs its own replication, whether it has the characteristics of reproduction, infection is the primary condition for judging a certain program as a computer virus. 2. After destructive computer poisoning, it may cause normal programs to fail to run, delete the files in the computer or be damaged to varying degrees. Destroy the boot sector and BIOS, and destroy the hardware environment.

3. Contagious computer virus infectivity refers to the fact that a computer virus infects its own replicas or variants to other non-toxic objects by modifying other programs, which can be a program or a certain part of the system. 4. Latent computer virus latent refers to the ability of computer viruses to attach to other ** parasites, and the invasive virus will not attack until the conditions are ripe, which will slow down the computer. 5. Covert computer viruses have strong concealment, and a few can be checked out by virus software, and covert computer viruses appear and change from time to time, and this kind of virus is very difficult to deal with.

6. People who can trigger computer viruses generally set some trigger conditions for virus programs, such as a certain time or date of the system clock, and the system runs certain programs. As soon as the conditions are met, a computer virus "strikes" and compromises the system.

A computer virus is a set of computer instructions or programs inserted by the compiler into a computer program that can destroy computer functions or data, affect the use of the computer, and can replicate itself.

Computer viruses are transmissible, hidden, infectious, latent, excitable, expressive, or destructive. The life cycle of a computer virus: development period, infectious period, incubation period, attack period, discovery period, digestion period, and extinction period.

Destructive. Viruses invade computers, often with great destructiveness, can destroy data information, and even cause a large area of computer paralysis, causing great losses to computer users. For example, common computer viruses such as Trojan horses and worms can invade computers on a large scale and bring security risks to computers.

Infectivity. One of the major characteristics of computer viruses is that they are contagious and can invade computers through USB flash drives, networks, etc. After the invasion, the virus can often spread, infect the uninfected computer, and then cause accidents such as large-scale paralysis.

With the continuous development of network information technology, viruses can achieve a wide range of malicious intrusion in a short period of time. Therefore, in the security defense of computer viruses, how to face the rapid virus infection has become an important foundation for effective virus defense, and it is also the key to building a defense system.

A computer virus is a very small (usually a few kilobytes) piece of code that constantly replicates itself, hides and infects other programs.

As a special program, computer virus has the following characteristics: (1) Unauthorized executability, computer virus is hidden in legitimate programs or data, and when the user runs a normal program, the virus is served.

The machine steals control of the system and is able to run it first, but at this time the user still thinks that the normal program is being executed;

2) Concealment, a computer virus is a short and concise executable program with high programming skills, which usually always tries to hide itself from being detected by users;

3) Infectiousness, contagiousness is one of the most important characteristics of computer viruses, and once a virus program invades a computer system, it spreads rapidly through self-replication.

4) Latent, computer viruses have the ability to attach to other viruses and parasitize, which we call the host of computer viruses. Relying on the parasitic power of the virus, the virus can quietly hide and then spread without the user noticing. (5) Expressive or destructive.

No matter what kind of virus program invades the system, it will affect the operation of the operating system to varying degrees. Even virus programs that don't directly have a destructive effect take up system resources. The vast majority of virus programs want to display some text or images, affecting the normal operation of the system, and some virus programs delete files, or even destroy the entire system and data, making it irretrievable, causing irreparable losses.

6) Triggerability: Computer viruses generally have one or several trigger conditions. Once the trigger condition is met or the infectious mechanism of the virus is activated, it is infected; Or activate the manifestation part of the virus or destroy the part. The essence of triggering is a kind of conditional control, and the virus program can carry out attacks under certain conditions according to the requirements of the designer.

This condition can be a specific character typed, a specific date or a specific moment, or a certain number of times the counter built into the virus is reached, etc.

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A computer virus is a computer program that is created by humans or non-humans and is capable of self-replication or operation without the user's knowledge or approval; Computer viruses often affect the normal operation of the infected computer, or are controlled without knowing it, and the normal operation of the computer only steals data, or is used for other purposes, and other non-spontaneous behaviors of the user.

FeaturesIn computer science, a computer virus is a biological virus that replicates itself and spreads to other hosts, causing damage to the host. The host is also a program, usually an operating system, which can further infect other programs, other computers. Computer viruses generally steal themselves during their spread, are triggered by specific conditions, and begin to wreak havoc.

Computer viruses have undesirable characteristics such as transmissible, hidden, infectious, latent, excitable, expressive, or destructive, and the program can usually be considered a virus by exhibiting two or more of the characteristics described above.

The life cycle of a computer virus is the development stage, the infection stage, the incubation period, the attack stage, the discovery stage, the digestion stage, and the extinction stage.

Panda burns incense (a computer virus).

Computer Virus:

A set of computer instructions or programs that are compiled or inserted into a computer program that destroys computer functions or destroys internal corrupt data, affects the computer's ability to be used and can replicate itself** is called a computer virus

virus）。

Key features:

Parasitic, destructive, infectious, latent, insidious, triggerable.

A set of computer instructions or programs that are compiled or inserted into a computer program that destroys computer functions or destroys data, affects the use of the computer, and is capable of self-replication** is called a computer virus

virus）。Destructive, replicable and contagious.