Most damage doesn't come from the break-in itself — it comes from how far an intruder can move once they're inside. A single phished laptop can become a route to your servers, your backups and your shared files.
Internal testing assumes an attacker already has that first foothold and measures how far they could reach across your network, so you know exactly which internal doors to close and in what order.
We're expanding this into a full guide.
In the meantime, see Penetration testing & vulnerability scanning, or talk to us about your setup.