Meaning of computer virus (what is it, concept and definition)

What is Computer Virus:

A computer virus is a malicious program or malware that contaminates the operating system of electronic systems such as computers or smartphones .

This program enters the system by being embedded within a common file in the form of a code. When executing the file, the “infectious” action of the virus is displayed.

The purpose of these viruses can range from a simple joke, to spying on personal information ( spyware ) or destroying files and computers.

Most of the time, this type of process is unnoticed by users. Hence the importance of protecting the operating systems of the devices with programs called "antivirus".

Characteristics of computer viruses

• They are kept dormant in the device's RAM, even when the program is not running. It does not necessarily manifest itself at the first contagion. They infect files on the hard disk. They spread to other devices through file sharing. They are executable, that is, they are parasitically hosted in other programs from which they are run. They only run or act when Scheduled conditions have been met, for example, a specific date or when a certain number of replications have been achieved on the device. They affect or prevent the development of the computer. Each virus has a specific objective: to slow down computers, destroy files, obtain secret information (for example, bank details), etc. They change from time to time, making it difficult to detect. Their effects are usually persistent, even after disinfection.

See also

• Malware.Spyware.Antivirus.

Types of computer viruses

There are a wide variety of computer viruses, but these can be broadly grouped into: viruses that affect files, called direct action viruses; and viruses that affect device startup, called resident viruses. A third type of virus has been added to this pair, called a Multipartite virus, which combines the two modes of action into one.

In any case, according to their objectives and methods, virus types are usually better known by the following names:

• Trojans: Also called Trojan horse, they intend to obtain personal information from the user without being detected by entering the system inadvertently. Backdoors: it is a "back door" that allows a third party to introduce infected files into the system. It is similar to the Trojan. Virus boot or boot virus: starts when you boot the operating system. Time bomb: they are those that reside silently in the system are activated only from a moment programmed by their creator. Macro viruses: are those that are embedded in files that contain macros, particularly doc , xls and ppt . When the file command is executed, virus commands are executed first. Worms: they are those that replicate within the computer system and spread through the internet (email), infecting everyone who receives messages from the infected account. Hijackers: this is a class of virus that controls the internet browser, changes the home page, adds advertising in pop-up windows, installs tools on the bar without the user's consent, and, finally, prevents access to certain web pages. Keyloggers: they are a type of virus that "captures the keys" and runs unnoticed to reveal what the user is typing on the screen. It is especially used to obtain passwords. Zombie: refers to viruses that allow remote control of the computer by a third party.