Optional appendix. Not a required install. Ubuntu is enough for every checkpoint in this stage.

What Kali is
Kali is a Linux distribution aimed at security testing. It bundles many tools. A bundle does not grant a target, and it does not replace the Ubuntu guest from Stage 02.

If you later choose a second guest
- Use a disposable guest, not your everyday system.
- Follow Kali's current virtualization page for the hypervisor you already learned. No checksum is supplied here; verify the current official image before installing it.
- Reuse the Stage 02 boundaries: NAT, no port forwarding, no shared folders, and no shared clipboard.
- Take a snapshot while the guest is powered off, before you change it. That snapshot restores the guest state it recorded. It does not rewind the host.
- Keep any lab browser, proxy, or certificate inside that guest.

Stop
If the grant is missing, stop. If a download page and the file you received disagree with a checksum you checked yourself, stop. This checklist does not supply a checksum.