If you would like to extract the contents of an NT backup (.bkf) file in Linux, mtftar is a utility that translates a Microsoft Tape Format (MTF) stream into the tar format. You can pick up mtftar from the authors site at http://gpl.internetconnection.net.

To get started, download the source code and compile.

$ wget http://gpl.internetconnection.net/files/mtftar.tar.gz
$ tar zxfv mtftar.tar.gz
$ cd mtftar
$ make
$ sudo cp mtftar /usr/bin/
- or -
$ su -c "cp mtftar /usr/bin/"

Using this utility is straight forward, as shown in the following example.