Kali Linux is an entire arsenal of penetration testing tools and will also be used as the development environment for many of the scanning scripts that will be discussed throughout this book.
Prior to installing Kali Linux in your virtual security testing lab, you will need to acquire the ISO file (image file) from a trusted source. The Kali Linux ISO can be downloaded at http://www.kali.org/downloads/.
After booting from the Kali Linux image file, you will be presented with the initial boot menu. Here, scroll down to the fourth option, Install, and press Enter to start the installation process: