“We Got Hacked Through Our Own Network” How Businesses Miss the Threats Already Inside

Your firewall and antivirus aren’t protecting you from what’s already plugged in.

You’ve got a firewall. You’ve got antivirus on every laptop. You’ve ticked the boxes, and as far as you’re concerned, the business is protected.

Then one day, someone plugs a personal device into a network port in a meeting room. Or a contractor connects to your Wi-Fi and brings a compromised laptop along for the ride. Or a smart TV, a printer, a forgotten access point from three years ago — any one of them becomes a doorway into your network that nobody’s watching.

This isn’t a hypothetical. It’s happening in businesses across the UK every day. And most of them have no idea until the damage is done.

The Myth of “We’re Covered”

The most dangerous assumption in business IT is that a firewall and antivirus software mean you’re secure. They’re important, but they’re only guarding the front door. The problem is, most breaches don’t come through the front door. They come through devices that are already inside.

Think about what’s connected to your network right now. Laptops, phones, tablets — fine. But also printers, IP cameras, smart displays, building management systems, IoT sensors, and whatever someone’s hotspot-sharing in the break room. Every single one of those is a potential entry point if it’s unmanaged, unmonitored, or misconfigured.

The Real Threat: Inside Your Network

Here’s a scenario that plays out more often than anyone likes to admit: a member of staff brings in a personal laptop to catch up on some work. They connect it to the office Wi-Fi. That laptop has been compromised — maybe through a phishing email at home, maybe through a dodgy download. Now their device has line of sight to internal resources it should never be able to reach.

Or there’s a device that’s been sitting in a cupboard, still powered on, still connected, still running firmware from 2019. It’s not on anyone’s asset register. It’s not being monitored. But it’s on your network, and it’s a vulnerability.

These aren’t edge cases. They’re everyday realities in businesses that assume their perimeter security has everything covered.

What You Can’t See Can Hurt You

The core issue is visibility. If you don’t have a way to see every device on your network in real time, you can’t control what connects, you can’t enforce policies, and you can’t respond to threats you don’t know exist.

This is exactly where a platform like Cisco Meraki changes the game. Meraki gives you a real-time view of every client on your network — what it is, where it is, how much bandwidth it’s using, and whether it should be there at all. You can set policies that automatically isolate unknown devices, segment your network so guest traffic never touches business systems, and get alerts the moment something unexpected connects.

But here’s the catch that trips businesses up: those security features — client isolation, network segmentation, advanced analytics, intrusion detection — aren’t just baked into the hardware. They’re tied to your Meraki licence. Specifically, they require the right licence tier to be active. If your licence has lapsed, or you’re running a basic tier that doesn’t include security features, you’ve got the hardware on the wall but you’ve lost the tools that actually protect you.

It’s like fitting a burglar alarm and letting the monitoring contract expire. The box is still on the wall, but nobody’s watching.

Where G5 Technologies Comes In

At G5 Technologies, we specialise in making sure your Meraki deployment is actually protecting your business — not just sitting there looking the part.

We start by auditing your current network to identify every device that’s connected, flagging anything that shouldn’t be there, and mapping out the gaps in your security posture. Then we configure your Meraki environment properly — network segmentation, access policies, device profiling, and alerting — so you have full control over what connects and what doesn’t.

Critically, we make sure your licensing is at the right level to support those security features and that it stays that way. We manage your renewals, monitor your licence status, and ensure you’re never unknowingly running without the protection you’re paying for.

Because the worst time to find out your security licence has lapsed is the morning after a breach.

Don’t Wait for a Wake-Up Call

If your current security strategy starts and ends with a firewall and antivirus, you’ve got blind spots on your network right now. The question isn’t whether unauthorised devices are connecting — it’s whether you’d know if they were.

Get in touch with G5 Technologies today.
We’ll show you exactly what’s on your network and make sure only the right things stay connected.