A program that detects or eliminates a computer virus. Some antivirus programs can detect suspicious activity on your computer as it happens; others must be run periodically as part of your normal housekeeping activities.
An antivirus program locates and identifies a virus by looking for characteristic patterns or suspicious activity in the system, such as unexpected disk access or .EXE files changing in some unusual way. It recognizes the virus by comparing information from the system against a database of known viruses, which is kept on disk.
Be sure you test an antivirus program carefully on your network before you employ it everywhere; some programs impose an enormous overhead on normal network operations.
See also file-infecting virus; macro virus; multipart virus; polymorphic virus; stealth virus; Trojan Horse; vaccine; virus.