Here's how you can add the BackTrack security repository in Ubuntu 12.10 or 12.04. 1. Open a terminal window. 2. Type in the following commands then hit Enter after each. wget -q http://all.repository.backtrack-linux.org/backtrack.gpg -O- | sudo apt-key add - sudo sh -c "echo 'deb http://all.repository.backtrack-linux.org revolution main microverse non-free testing' >> /etc/apt/sources.list" sudo apt-get update sudo apt-get upgrade 3. To check if it was added without a problem, use this command: sudo apt-get install backtrack-wallpapers
For more, see the original article at the link below.