[ The PC Guide | System Care Guide | Data Loss and Virus Prevention | Virus Detection and Protection | Virus Scanning and Antivirus Software ]

Virus Definition Files

Conventional virus scanners rely on virus definition files to perform their work. These files (there may be only a single file for some scanners) contain the patterns that they use to identify viruses. The definition files tell the scanner what to look for to spot viruses in infected files. Most scanners use separate files in this manner instead of encoding the virus patterns into the software, to enable easy updating.

Most commercial virus scanners update their virus definition files on a monthly basis, as new viruses are found "in the wild" and definitions created for them by the programmers that write the antivirus software. These updates are normally made available for download at the software company's web site or BBS system. It is critical that you update your scanner's virus definition files on a regular basis: preferably each month, but no more than every three months if monthly is impossible. A scanner that is out of date will still find older viruses (and to be fair, many of them have been around for ages) but will leave you unprotected against newer menaces.

Some programs actually update not only the virus definition files, but also parts of the scanner program itself (a program patch) when you update the virus definitions. This is sometimes required when a new virus type necessitates a change in how scanning is done by the software.

Next: Virus Removal and Recovery

Home  -  Search  -  Topics  -  Up