NTBackup

Windows NTBackup is backup/archiving software utility included in Windows NT 3.51, Windows NT 4.0, Windows 2000, Windows XP Pro, and Windows Server 2003.

File Information
Windows NTBackup would backup a file or a folder into a BKF file. It has been replaced by the wbadmin command.

Format Information
BKF backup files begin with the ascii  or hex values