Repository

http://launchpad.net/~backbox/+archive/four

This PPA can be added to your system manually by copying the lines below to your "/etc/apt/sources.list.d/backbox-four-trusty.list" file:

deb http://ppa.launchpad.net/backbox/four/ubuntu trusty main
deb-src http://ppa.launchpad.net/backbox/four/ubuntu trusty main

Then add the gpg key used to sign the packages by running the following commands at your command prompt:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 78A7ABE1
sudo apt-get update

Now BackBox Repository is installed, run the following commands at your command prompt:

sudo apt-get update
sudo apt-get install {package_name}