It can be hidden in the storage medium (or program) of the computer in some way, and will be activated when certain conditions are met. By modifying other programs, it will put its exact copy or possible evolutionary form into other programs, thus infecting other programs and destroying computer resources.
According to the media where the virus exists:
1. Network virus: Spreading executable files in infected networks through computer networks.
2. File virus: it infects files in the computer (such as COM, EXE, DOC, etc.). ).
3. Bootable virus: It infects the boot sector and system boot sector (MBR) of the hard disk.
4. Mixed virus: The above three situations combine virus types. This virus usually has complicated algorithms. They use unconventional methods to invade the system, and at the same time use encryption and deformation algorithms.
Extended data
Prevention and control methods of computer virus
1. Don't download files casually. If necessary, check for viruses immediately after downloading.
2, install antivirus software and firewall, and pay attention to upgrade the virus database in time, regularly check the computer antivirus, check the disk antivirus before each use.
3. Update Windows regularly. Windows Update is an online extension of Windows, which is used to keep the computer up-to-date and get the latest updates and patches to protect the computer and make it run smoothly.
Baidu Encyclopedia-Network Virus
Baidu Encyclopedia-Computer Virus