Computer virus ) Viruses )

-: Definition of viruses

Computer virus is defined as a type of malware that is designed to spread from one computer to another. With the aim of causing damage to the data and information contained in those devices or even to their operating systems, the virus is transmitted between devices by attaching itself to a program or file; Where it remains dormant during it until the appropriate conditions are created that allow it to implement its software commands that would infect the device with viruses, as when a program loaded with a computer virus is running; The virus copies itself and moves to stored files or other programs on the device. The reason for naming viruses by this name is due to how they spread and multiply across devices, as once any file or program on a computer is infected, the virus infection quickly spreads and moves to infect other files and programs on the device. It is worth noting that there are two main conditions that must be met in any computer. A program to be identified as a computer virus, which are as follows: The ability of the program to copy its commands and code in different parts and places on the computer. The ability of the program to execute itself automatically through the device, as viruses execute their own code commands instead of executing the commands of the programs in which they reside.

-: History of viruses 

The idea of viruses emerging dates back to 1966 AD. This is when the American scientist John von Neumann published a research paper entitled The Theory of Self-Reproducing Automatic, where Newman indicated in his research the possibility of developing computer programs capable of automatically copying themselves while working through a computer, although Newman did not call the programs he aspired to create viruses; However, it gained that from its spontaneous nature in work and self-sustainability. The emergence of the first idea of ​​creating computer viruses was motivated by scientific and research only, and it is the same justification that led to the emergence of the first viral program in history. Bob Thomas, a BBN employee, created a computer program capable of copying itself through every device that accesses it, and Thomas wanted through the creation of this program to prove the possibility of realizing Newman's vision and research ideas that he put forward in the thesis of the theory of automatic self-replication, and this program was known as ( Creeper), and it did not cause any damage to the device to which it was transmitted. The goal of making viruses has changed from experimental scientific goals to harmful subversive goals. The year 1974 AD witnessed the emergence of what was known as the Rabbit virus, followed by the emergence of a new type of harmful viral program in 1975 AD. This is what is known as the Trojan virus. It is a viral program that spreads by including itself with programs, files, or even games that run on a computer, and computer viruses continued to appear and progress significantly, but until 1983 AD these programs were not yet known as viruses; This is when engineer Fred Cohen introduced this term to refer to malware that infects computers. 

-: How viruses work

 The viral program requires appropriate conditions to start working across devices, as once the virus successfully embeds itself in a program or file; It remains static without showing any signs or symptoms of infection of the device with the virus, but as soon as the program that contains the virus is running, it starts executing the instructions of the virus program instead of executing the instructions of the required program, and once the device is infected, the infection can be transmitted from the device to other devices in the network

-: Ways of virus transmission

: Viruses are transmitted to devices through many methods, including the following

.email attachments

. Unofficial electronic programs and services

.Files downloaded from the Internet

.various storage media; like hard disks

.Text messages via mobile phones 

.Fake links via various social media

-: Virus damage 

:Viruses often cause many damages to the computer, and it is worth noting that these damages are signs of infection with viruses, and among these damages are the following

.Delete files automatically

. The appearance of messages indicating errors in some programs or files that are running on the device 

.The slowness of the operating system in which the device is running, or its freezing at times 

Disable some ports on the device

 .An error in the work of some keyboard keys

.Change the size of files on the device

.Change the size of the memory, whether by increasing or decreasing the size

. unusual device activity; Like changing passwords

.Pop-up windows appearing repeatedly on the device screen

-: Virus properties

: There are many characteristics that are distinguished by certain types of computer viruses, while others do not have all of these characteristics, including the following

Polymorphism: Some types of viruses are characterized by their ability to change their shape according to many variables, and these viruses can change their access to different devices

Stealth: Viruses can attach themselves to other files on the computer, which allows them to remain hidden within those files so that they can start their malicious work on the device

Infection with other viruses: Computer viruses can be infected with other viruses, because they are just software commands that can be infected like any other program on the computer, and this leads to making the device infected with more than one virus at the same time Even if the computer is fully formatted, especially if the infection spreads to the backup copies that restore the user’s information and data to the device through it.