Symantec 10551441 Administration Guide - Page 145

4 Chapter Updating virus definitions files This chapter includes the following topics: ■ About virus definitions files ■ Virus definitions files update methods ■ Updating virus definitions files on Symantec AntiVirus servers ■ Updating virus definitions files on Symantec AntiVirus clients ■ Controlling virus definitions files ■ Testing virus definitions files ■ Update scenarios ■ About scanning after updating virus definitions files About virus definitions files Virus definitions files contain sample code for thousands of threats. When Symantec AntiVirus scans for threats, it attempts to find matches between your files and sample code that is inside of the virus definitions files. If Symantec AntiVirus finds a match, the file may be infected. Every server and client that runs Symantec AntiVirus has a copy of the virus definitions files. These files can become outdated as new viruses and other threats are discovered. Symantec updates virus definitions files about once a week, or more frequently if needed. It's important to keep virus definitions files current to maintain the highest level of protection for your network.