How to Download Kali linux.

Kali Linux is a Debian-based Linux distribution aimed at advanced Penetration Testing and Security Auditing. Kali contains several hundred tools aimed at various information security tasks, such as  Penetration Testing, Forensics and Reverse Engineering.
Kali Linux is developed, funded and maintained by Offensive Security, a leading information security training company.

Kali Linux was released on the 13th March, 2013 as a complete, top-to-bottom rebuild of BackTrack Linux, adhering completely to Debian development standards.
You can download kali at :
https://www.kali.org/downloads/

Download the iso file for virtual box you can choose between the 64-bit or the 32-bit one.
You can download it very easy so enjoy and see you later bye.