Setting Up a VM

Pick a hypervisor (see Tools), download an ISO, create the VM. That is the whole process.

The details differ by tool, but the steps below are universal.

Step 1 — Choose a Guest OS

For security work, start with one of these:

Kali is the default choice for offensive security. Ubuntu is better if you want to learn Linux from scratch without preinstalled noise.

Download the ISO from the official site. Verify the checksum before using it.

Step 2 — Create the VM

In your hypervisor, create a new VM and point it at the ISO. Standard recommended specs:

Do not over-allocate. Your host machine needs resources too.

Step 3 — Network Modes

Choose based on what you need:

Start with NAT. Switch to host-only or internal when you set up attack/defend lab environments.

The lab recipe: put the attacker VM and the target VM on the same host-only or internal network, so they see each other and nothing else. Give the attacker a second adapter on NAT when it needs to download tools. Inside a VM, ip a shows which network it landed on, and ip r shows whether it has a gateway. Two VMs that cannot see each other are almost always on different adapter types.

Step 4 — Take a Snapshot

Before you install anything or run any tools, take a snapshot. Name it something useful like clean-install.

When things break — and they will — revert and start from a known good state.

Take one more before every experiment: an unknown binary, a CTF file, a script from a writeup. Snapshot, run it, revert. A snapshot is not a backup. It lives on the same disk as the VM, so it does not survive the disk.

Recommended First Steps After Install

# Update the system
sudo apt update && sudo apt upgrade -y

# Check your IP address
ip addr show

# Check you can reach the internet
ping -c 4 google.com

References

• Kali Linux documentation
• VirtualBox manual
• VMware documentation