Mainly achieved by "destroying computer programs and data". A computer virus is a set of computer instructions or program codes that are artificially created to destroy computer functions or destroy data, affect the normal use of the computer, and are capable of self-replication. 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.
The operating environment of this tutorial: Windows 7 system, Dell G3 computer.
At present, the harm caused by computer viruses to computers is mainly achieved by "destroying computer programs and data."
Computer virus refers to a set of computer instructions or program codes inserted by the programmer into a computer program that destroy computer functions or destroy data, affect the normal use of the computer, and are capable of self-replication.
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 recognized as the number one enemy of data security. Since 1987, computer viruses have received widespread attention around the world. Computer viruses were first discovered in my country in 1989. Currently, new viruses are developing in directions that are more destructive, more secretive, have higher infection rates, and spread faster. Therefore, it is necessary to learn the basic knowledge of computer viruses in depth and strengthen the prevention of computer viruses.
Classification of media types that computer viruses depend on
(1) Network viruses: Computer viruses that infect executable files through computer networks.
(2) File viruses: viruses that mainly attack files in the computer (files with an extension of .EXE or .COM). When the infected files are executed, the viruses begin to damage the computer. This kind of virus It is disguised as a game, adult video software and other phishing forms to trigger users to click, and the virus will be installed obviously or secretly.
(3) Boot virus: It is a virus that mainly infects drive sectors and hard disk system boot sectors.
Path of transmission
Computer viruses have their own transmission modes and different transmission paths. The main function of the computer itself is its own replication and propagation, which means that computer viruses can spread very easily, and viruses can usually be spread in an environment where data can be exchanged. There are three main types of computer virus transmission methods:
(1) Virus transmission through mobile storage devices: U disks, CDs, floppy disks, mobile hard disks, etc. can all be paths for spreading viruses, and because they often are moved and used, so they are more likely to be targeted by computer viruses and become carriers of computer viruses.
(2) Spread through the Internet: The network methods described here are also different. Web pages, emails, QQ, BBS, etc. can all be ways for computer viruses to spread online. Especially in recent years, with the advent of network technology, With the development of the Internet and the operating frequency of the Internet, the speed of computer viruses is getting faster and faster, and their scope is gradually expanding.
(3) Spread by exploiting the weaknesses of computer systems and application software: In recent years, more and more computer viruses have spread by exploiting the deficiencies of application systems and software applications. Therefore, this approach is also classified as a basic category of computer viruses. in the mode of communication.
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