The virus signature, also known as virus definition, is a unique binary string that represents a part or the entirety of a computer virus. In a similar way to fingerprints, it helps identify specific viruses. Antivirus software uses virus signatures to precisely detect malicious codes.

Bitdefender uses an incremental virus signature system based on two file types, cvd and ivd. The first contains the main collection of virus signatures, while the second stores only the latest updates. Once every three months, Bitdefender downloads an updated version of the cvd file and ivd is reset to 0. This allows for small daily virus signatures updates.

In order to further optimize the update transfers and the scan speed, similar virus signatures are combined into a single pattern, specific for an entire virus family. This process reduces the number of virus signatures displayed in the product, without adversely affecting the virus detection.

Bitdefender allows automatic download of virus signatures, or they can be downloaded as separate packages.

Applies to: Bitdefender Antivirus, Bitdefender Antivirus 2008, Bitdefender Antivirus 2009, Bitdefender Antivirus 2010, Bitdefender Antivirus Plus, Bitdefender Antivirus Scanner for Unices, Bitdefender Client Professional Plus, Bitdefender Client Security, Bitdefender Client Standard, Bitdefender Enterprise Manager, Bitdefender Free Edition, Bitdefender GameSafe, Bitdefender Internet Security, Bitdefender Internet Security 2008, Bitdefender Internet Security 2009, Bitdefender Internet Security 2010, Bitdefender Mobile Antivirus, Bitdefender Online Scanner, Bitdefender Security for Exchange, Bitdefender Security for File Servers, Bitdefender Security for ISA Servers, Bitdefender Security for Mail Servers (Linux), Bitdefender Security for Mail Servers (Windows), Bitdefender Security for Samba, Bitdefender Security for SharePoint, Bitdefender Total Security 2008, Bitdefender Total Security 2009, Bitdefender Total Security 2010, Bitdefender Client Security (Windows)

Operating Systems: Debian/Ubuntu, Fedora, FreeBSD, Mandrake, Red Hat, Slackware, SUSE, Windows 2000, Windows 2003, Windows 2008, Windows 98, Windows Me, Windows NT, Windows VISTA, Windows XP