Every computer owner knows: if a “faithful friend” has stopped obeying commands, responding to mouse clicks and starting to “freeze”, it means he is “sick”. A malicious program has been introduced into the computer system. Viruses classification
which are very diverse, created exclusively for the destruction of computer systems. Once launched, the malware multiplies, destroying other applications and files.
Viruses enter a computer in various ways. Sometimes they enter the system through infected media - disks or flash cards, but most often the system is infected with “pests” via the Internet or electronic messages. With the development of small local networks, network viruses have appeared that destroy all computers connected by a network.
Malicious programs are classified according to various criteria. There is a classification of viruses in which they differ in “habitat”. According to this system, viruses are divided into file, boot and file-boot. File varieties are “fed” by program files with extensions such as COM, EXE, BIN, SYS, BAT and others. Boot viruses settle in the boot sector of the disk and run with the OS. File-boot "pests" combine the properties of the two previous species.
Another virus classification sorts malware programs by launch type. Non-resident species of this classification are launched only once. Such "disposable pests" do not infect system memory and do not last long. Resident viruses, in contrast, populate RAM and infect the system after each start.
Malicious programs also differ by the method of disguise. This classification of viruses consists of masked and non-masked “pests”. Non-masking viruses do not try to hide their malicious essence, while masked viruses are also divided into types. Self-encrypting programs are automatically decrypted before starting. Invisible "stealth viruses" are well camouflaged - they cannot be detected in the host program before launch. Mutating types are constantly changing, so they are most difficult to detect and “cure”.
Most vi
Russ - only part of any useful program. However, there are pests that are themselves made in the form of a useful program. Such software viruses also come in many forms.
Trojans usually take the form of an interesting game. After launch, such a game begins to gradually destroy the system. Trojans do not know how to multiply and destroy other programs, but they act constantly. Some, more advanced trojans launch themselves at any particular time. Replicator programs, or worms, live on the Web. For their reproduction other programs are not required. "Worms" stuffed with viruses spread on the Web and destroy all systems connected to it. Some viruses are created to destroy products of certain programs, for example, Word or Exel documents.
No matter how extensive the classification of viruses, pest control is possible and necessary. Antivirus programs such as Eset Nod32 and Kaspersky Anti-Virus are involved in the prevention, diagnosis and treatment of PC systems. They are especially necessary if the system is constantly connected to the Internet.