A computer virus is a type of malware that is designed to spread from one computer to another. With the aim of harming the data and information contained in those devices or even 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 execute its programming commands that would infect the device with viruses, as when running a program loaded with a computer virus; The virus copies itself and moves to stored files or other programs on the device.
The reason for naming viruses with this name is due to how they spread and multiply across devices, as once any file or program on the computer is infected, the infection with the virus quickly spreads and moves to infect files and other programs on the device, It is worth noting that there are two main conditions They must be present in any program in order for it to be recognized as a computer virus, and they 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 across the device, as viruses execute their own program commands instead of executing the commands of the programs in which they are located.
The idea of the emergence of viruses 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 Neumann pointed out in his research the possibility of developing computer programs capable of automatically copying themselves while they are working through a computer. ,and although Newman did not launch those programs that aspiration to create the virus name; However, it gained this from its spontaneous and self-perpetuating nature.
The emergence of the first idea of creating computer viruses was motivated by scientific and research only, which is the same justification that led to the emergence of the first viral program in history; As Bob Thomas, a BBN employee, created a computer program capable of copying himself across every device he accesses, and by creating this program, Thomas wanted 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-reproduction, and this was known The program is called (Creeper), and it did not cause any damage to the device to which it was transferred.
The goal of the virus industry has changed from experimental scientific goals to harmful disruptive goals; The year 1974 witnessed the emergence of what was known as the Rabbit virus, followed by the emergence of a new type of malicious virus in 1975. This is known as a Trojan virus (Trojan); It is a viral program that spreads by embedding itself in programs, files, or even games that run on the computer, and computer viruses continued to appear and progress remarkably, but until 1983 these programs were not yet known as viruses; That’s when engineer Fred Cohen introduced the term to refer to malware that infects computers.
Virus mechanism of action
A virus program requires appropriate conditions to start operating across devices, as once the virus itself is successfully embedded in a program or file ; It remains dormant without showing any signs or symptoms of infection with the virus, but as soon as the program containing the virus is run, the instructions of the virus program begin to execute 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.
Virus transmission methods
Viruses are transmitted to devices through many ways, including the following:
- Email attachments .
- Informal electronic programs and services.
- Files downloaded from the Internet.
- various storage media; like hard disks.
- Text messages via mobile devices.
- Fake links on various social media .
Viruses often cause many damages to the computer, and it is worth noting that these damages are signs that the device is infected with viruses, and these damages include the following:
- Automatically delete files.
- Messages appearing indicating errors in some programs or files that are running on the device.
- The operating system in which the device is running is slow, or sometimes freezes.
- Disable some ports across the device.
- Error in the work of some keyboard keys .
- Change the size of files located across the device.
- Memory size changes either by increasing or decreasing the size.
- Abnormal activities appearing across the device; Like changing passwords.
- Pop-ups appear frequently across the device screen.
There are many characteristics that characterize 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 also change the ways they reach different devices.
- Incognito: 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 across the device.
- Infection with other viruses: Computer viruses can infect 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.
- Permanence: Some types of viruses are characterized by their ability to infect different parts of the device, which allows them to return to it even if the computer is fully configured , especially if the infection spreads to the backup copies that retrieve the user’s information and data to the device through them.