I will start by mentioning one item and then moving on. If you are not familiar with Linux then how do you know that your machine was hacked?
OK. Let's put that issue aside.
The next thing is that you say that your backups are made by using Norton Ghost. That product doesn't work on Linux.
OK. Let's put that issue aside as well.
It seems that you are mainly interested in mounting the partitions of the backup drive. The first thing is to be able to see what is already mounted. You use the mount command with no parameters to see what partitions are mounted.
/dev/hda6 on / type ext3 (rw)
none on /proc type proc (rw)
none on /proc/bus/usb type usbfs (rw)
none on /sys type sysfs (rw)
/dev/hda5 on /var/sys.common type ext3 (rw,noexec)
/var/sys.common/tmp.loop on /tmp type ext3 (rw,noexec,loop=/dev/loop0)
/var/sys.common/var-tmp.loop on /var/tmp type ext3 (rw,noexec,loop=/dev/loop1)
/var/sys.common/folding-home.loop on /var/my.chroot type ext3 (rw,loop=/dev/loop2)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/mapper/truecrypt0 on /home type ext3 (rw,noexec,nosuid,sync)
Here you can see in the first line generated by the mount command that /dev/hda6 is mounted on / and that it has an ext3 file system and it is mounted read-write.
If I read your post correctly you are mounting each of the partitions of the backup drive to /mnt of the running system. Hopefully you are only mounting one partition at a time and you unmount one partition before you mount another. Technically speaking you don't have to unmount one partition before you mount another but let's keep things simple. Just to be sure we are talking about the same thing here is an example of a mount command.
mount /dev/hdb3 /mnt
That should work if there is a valid file system even if there is no entry in the running system's /etc/fstab file. If you want to add a line to /etc/fstab this would work for any file system.
/dev/hdb3 /mnt auto defaults 0 0
That line tells Linux to figure out what kind of file system is on the partition.
So now you have /dev/hdb3 mounted on /mnt. You want to see what is on the partition.
You should see at least two lines. The first line just has a dot and the second line has two dots.
ls -la /mnt
drwx------ 2 root root 1024 May 6 05:28 .
drwxr-x--- 32 root root 3072 May 6 05:28 ..
Post back and let us know if this is what you have done and this is what you see. I just wanted to make sure that what you are doing and what you are seeing is what your post appears to say.