You want to know the purpose of the .vbn files in the Quarantine folder on a Symantec AntiVirus Corporate Edition or Norton AntiVirus Corporate Edition server, and whether they can or should be deleted.
The .vbn files are files that have been placed in Quarantine. The extension .vbn stands for Virus Bin. Quarantined items and backup items all have the .vbn extension. If you want to delete these files, Symantec recommends that you only delete these .vbn files through the Norton AntiVirus Corporate Edition or Symantec AntiVirus Corporate Edition user interface, or by using the Symantec System Center. These views display information such as the original file name and the reason that the file was placed in Quarantine, so that you know exactly what you are deleting. These files can be deleted through the Windows Explorer if necessary, but in most cases this is not recommended.