We will now crack Linux password with John the Ripper:
- With your Windows machine off start by going into VirtualBox, clicking on the Linux VM, and click on Settings:

- From the settings menu click Storage. Click on the CD-ROM drive and choose the Kali ISO that you recently downloaded. Then click OK:

- Now start your Linux VM and it should automatically load the Kali CD. From the main menu select Live (forensic mode).