What is a VDF?
- VDF is the abbreviation for "Virus Definition File" and is created by the Avira Virus Lab.
- The VDF is part of almost every Avira product and contains information (fingerprint, detection rules) to identify malware in files.
- The update of the VDF takes place on a regular basis (currently up to 8 times a day).
- The first VDF started back in the 90s with a single container file (monoVDF). Due to the malware growth the VDF increased likewise and the customers had to update the complete VDF file even on small changes. The remedy of that situation was the iVDF which included 4 VDF container files that could be updated separately.
- The past VDF generation is called nVDF with an amount of up to 32 container files. With this mechanism, all stored data in the VDF can be downloaded redundant.
- During the last years the VDF loading time increased as more and more detection have been added to the VDF. Therefore xVDF has been created which includes a various number of VDF container files and a supports a faster loading of the VDF files.
What is an xVDF?
xVDF is the abbreviation for "e(x)tended Virus Definition File" and is the successor of the VDF format before (nVDF).
What are the benefits of xVDFs?
With the xVDF mechanism, the update volume of VDF files is reduced to a minimum. This allows us to keep the VDF files as small as possible. Another improvement is the VDF loading time. The CPU resource consumption when loading the VDF files will be as well reduced.
How do we achieve a smaller download volume with xVDF?
With xVDF for our Windows products, this number is set to 256 AND we created the flexibility to change the number of files at any time if needed. For our Android product, we start with 32 xVDFs. As there are more VDF files available, new VDF data can be distributed as independent VDF file.
How do we achieve the faster loading of xVDF?
xVDF update files will be downloaded and merged into one single VDF file locally on the client machine (local.vdf). Instead of loading and merging the downloaded VDF files on scan startup, the scan engine just loads the single cache VDF file which was created after an xVDF update.
What are the xVDF file names for our Windows products?
With xVDF the file name for Windows products prefix changed to xbv, followed by a number. The file name extension is .vdf.
What are the xVDF file names for our Android product?
With xVDF for Android, the file name prefix is xba, followed by a number. The file name extension is .vdf.
- Android xVDF