In order to perform the crack / recovery, we are going to use a small utility called xlcrack, xlcrack recovers lost or forgotten passwords from XLS files such as those created by Microsoft Excel. Some newer XLS files are not suitable for password recovery using this software.
Install libgsf-1
kartook@Nilas:~$sudo apt-get install libgsf-1-dev
Download and compile xlcrack
kartook@Nilas:~$wget http://freshmeat.net/urls/1d5772c1c5bea2854e1d04b29f1f772a
kartook@Nilas:~$tar zxvf xlcrack-1.2.tar.gz
kartook@Nilas:~$cd xlcrack-1.2
kartook@Nilas:~$make
How to Crack / Recover A Password From a XLS-file
kartook@Nilas:~$./xlcrack password_protected_spreadsheet.xls
password_protected_spreadsheet.xls: 1234
