In every tutorial in this section (Nmap, hping3, Wireshark, Metasploit, hashcat, airodump-ng), we assumed you already had a ready Kali Linux environment. Now it's time to start from zero: actually installing Kali Linux, as an isolated, safe virtual machine on your own computer.
Why a virtual machine, not a direct install?
Installing Kali as a VM (instead of directly on hardware or dual-boot) has several big advantages: it's completely isolated from your main OS (if something breaks, you just wipe that one VM), you can take snapshots and roll back to a clean state at any moment, and you can build a "vulnerable target" VM right alongside it for practice — exactly the environment every tutorial in this section assumes.
Prerequisite: install a virtualization program
First, install one of these two (both free):
VirtualBox — from virtualbox.org, simpler and lighter to start with.
VMware Workstation Player — from vmware.com, slightly better performance on some systems.
This tutorial uses VirtualBox; the steps on VMware are nearly identical.
Step 1: Download the ready-made Kali virtualization image
Instead of downloading a raw ISO and going through the whole Linux install process, the Kali team publishes a ready Virtual Machine Image (.ova format for VirtualBox) that imports in minutes:
Go to kali.org/get-kali.
Select Virtual Machines.
Download the VirtualBox version (.7z or .ova format).
Step 2: Import the file into VirtualBox
Extract the downloaded file (if it's .7z). Then in VirtualBox:
From the menu, select File > Import Appliance.
Point it to the .ova or .vbox file.
You can bump up the default settings (RAM, CPU count) right there — at least 4 GB RAM is recommended for a smooth experience.
Click Import and wait for the process to finish (a few minutes).
Step 3: First boot and login
Double-click the newly created VM to power it on. Once it boots, you'll see the login screen. Kali's default credentials:
username: kali
password: kali
(On newer versions, the system may prompt you to change this password on first login — make sure to do it.)
Step 4: Update the system immediately after install
The first thing to do after logging in is open a terminal and run:
sudo apt update && sudo apt full-upgrade -y
This updates the package list and upgrades every pre-installed tool (including the same Nmap, Wireshark, and Metasploit we used in earlier tutorials) to the latest version.
Step 5: Enable Guest Additions (for a better experience)
To be able to go full-screen and move files between your main computer and the VM, from the VirtualBox menu select Devices > Insert Guest Additions CD image, and inside Kali run:
sudo apt install -y virtualbox-guest-utils
After a restart, the screen resolution automatically adjusts to match your window size.
Step 6 (recommended): build a separate "target" VM
To practice tools like Nmap or Metasploit, you need a target — never try these tools against a real network or someone else's system. Free, legal training VMs like Metasploitable2 or DVWA are built exactly for this purpose, and you can install them the same way (import into VirtualBox) on the same internal virtual network.
Why does this first step matter so much?
Every other tutorial in this section — from scanning with Nmap to cracking with hashcat — runs on this exact environment. A clean, up-to-date install is the reliable foundation for genuinely learning penetration testing — exactly the starting point my security and penetration testing courses begin from too.
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