A computer virus is a program code that acts by analogy with a biological virus. It is embedded in the system, creates its own copies and causes massive infection of files first on one computer, and then on others, up to a global web pandemic.
Viruses have diverse functionality, but most often they damage or destroy data. In the easiest case, infection leads to “brakes” of the OS, they are also one of the first signs that a virus has started in the computer.
Information security audit
There are viruses that can damage the hardware of a computer. In 2015, hackers from the Equation cyber group created a virus that changed the firmware of the hard drive and actually disabled it. Formatting didn’t help, and flashing was so time-consuming that it was easier to replace the disk.
Until then, the virus may not manifest itself in the system in any way. The “incubation period” is replaced by an active stage when the user launches an infected program, which in turn activates the virus code.
Viruses usually spread over the network — for example, by e-mail, in the format of a mail attachment, through social networks (in messages, links) and malicious sites. Distribution through physical media, especially USB drives, is still relevant.
Viruses are often integrated into seemingly legitimate software. This can be avoided by downloading programs only from the official websites of manufacturers (no torrents).