Hackers Turned Up the Heat on Hundreds of French Supermarket Fridges. What It Means for the Smart Devices on Your Network.

Your refrigerator is going to get you.

Not really. But there was a story in the news this week about hackers breaking into refrigerators at supermarket chains in France, and what they were able to do was turn the temperature up and make a whole lot of food go bad.

It's an interesting one, and it's exactly the kind of thing we think about in security.

What happened in France

On the night of October 12, someone got into the refrigeration systems at hundreds of supermarkets across France. At least 300 Intermarché and Netto stores were hit, more than 100 Coopérative U outlets, 80 Carrefour supermarkets, and a share of Monoprix's stores. Fridges and freezers ran as high as 50°C (122°F). By morning stores were throwing food away, and several had fires.

The Paris prosecutor called it a large-scale attack on "connected refrigerators" at several major food retailers. The prime minister ordered France's national cybersecurity agency to investigate. As of this writing nobody has claimed it.

Here's the part I want you to notice. Nobody hacked a cash register. Nobody hacked a laptop or a server. They went in through the refrigeration controllers, the small networked boxes that keep the cold cases cold. Equipment nobody thinks of as a computer.

Why a fridge is a security problem

You have a network, and you have a lot of things on that network. Some of them are old. Some of them haven't been patched in years and never will be. Those are the ones that are vulnerable to attack.

Walk around your office and count them:

• The thermostat and the HVAC controller.
• The security cameras and the video recorder they feed.
• The door controller and the badge readers.
• The printers and copiers.
• The TV in the conference room.
• Every phone your employees carry in and connect to the Wi-Fi.

Most of those were installed by whoever sold them, set up once, and never touched again. Nobody updates the firmware on a badge reader. Nobody changes the default password on the camera recorder. They just work, so nobody looks at them.

The problem is that attacking one thing usually gives you access to the next thing. If all of those devices sit on the same network as your file server and your accounting system, an attacker who gets into the cheapest, oldest box in the building can start looking around from there.

The fish tank story

The classic example is a casino. A few years ago a casino in North America had an internet-connected thermometer in a lobby fish tank. It was there to monitor the water. Attackers got into the thermometer, and from there they reached the casino's network and pulled out its database of high rollers.

A fish tank. That was the way in.

It sounds like a joke until you look at your own network and realize you have a dozen fish tanks of your own.

Segment the network

What we do for every client, and what we recommend for every network, is segmentation. As much as possible, we separate the things that need to talk to each other from everything else. A refrigerator isn't talking to an accounting system. A fish tank isn't connected to a point of sale system.

In a small or medium-sized office, that usually looks like this:

1. Smart devices get their own network. Cameras, printers, door controllers, thermostats, TVs and anything else with a plug and an IP address go on a separate network from the computers that hold your data. If one of them gets compromised, the attacker is stuck in a room with other printers.

2. Guests and personal phones get their own network too. Employees come in with their phones and connect them. Visitors ask for the Wi-Fi password. None of those devices are yours, and none of them need to reach your file server. Put them on a guest network that goes to the internet and nowhere else.

3. Each device can reach only what it needs. The camera recorder needs to reach the cameras. The printer needs to receive print jobs. Neither one needs to browse your accounting system. The firewall rules between networks should say exactly that, and block everything else by default.

4. Default passwords get changed, and firmware gets updated. Every device that ships with admin/admin gets a real password on day one. Firmware updates go on a schedule, like your computers.

5. Old equipment that can't be updated gets replaced or walled off. If the vendor stopped releasing updates years ago, that device is a permanent hole. Replace it, or put it on a network segment so isolated that it doesn't matter.

None of this is glamorous. On a normal day you'll never notice it's there. It matters on the day something cheap and forgotten gets compromised, because that's the day the attacker finds out they can't go anywhere.

Where to start

You don't need to rebuild your network this week. Start with an inventory.

1. Make a list of everything on your network that isn't a computer or a phone. Your firewall or router can usually show you every connected device.
2. Mark anything you don't recognize, anything older than five years, and anything nobody has updated.
3. Check whether those devices sit on the same network as your file server, your accounting system and your point of sale.

If the answer to that last one is yes, that's the gap. Network segmentation is a big deal, and security overall is a big deal. It should happen in every network, and the supermarkets in France are the reason why.

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One question to answer this week: what's the oldest device on your network, and what can it reach? If you don't know, run our free external scan to see what's visible from the outside, or book 15 minutes and we'll walk through what's sitting on your network and what it can talk to.

Keith Parker is the CEO of Methodology IT, a managed IT services provider in Los Angeles that has supported healthcare practices, nonprofits, and growing businesses across Southern California since 1997.

Sources: Al Jazeera, Oct 13, 2026 · LBC: hackers cause chaos in French supermarket fridges · Entrepreneur: the casino fish tank