What's connected to your network? Lessons from the freezer attacks

Last month, attackers turned up the fridges and freezers in hundreds of French supermarkets to 50°C [1] [2]. This week they hit more shops across Europe, and a few UK suppliers too [3] [4].

It wasn't sophisticated. The controllers were on the internet, run remotely by contractors, often with guessable passwords and years past their support date [3].

Now look around your own office.

CCTV. Door access. Heating and air con. Alarm panels. Lighting. The printer. The meeting room screen. The smart plug someone brought in.

Most of it was bought by facilities or installed by a contractor. Much of it sits on the same network as your laptops and client files. Plenty still has the installer's password, and the supplier can reach it from anywhere [5].

Each one is a small computer your firm doesn't manage.

I've seen this up close.

A bank whose third-party CCTV monitoring used the same username and password on every camera in every branch. It never expired.

An old door access system so easy to bypass that people kept turning up where they had no business being.

A CEO who didn't want the bother of an access card, so the exec suite and boardrooms stayed unlocked. Until people were found sleeping in them at weekends.

Nobody needed to hack anything.

Three questions every board should be able to answer:

1. What's connected to our network?
2. Who has access to it?
3. Who has control of it?

What to do this week

None of this calls for new technology. It needs someone to own the list and a supplier held to a contract.

• Walk the building with your IT lead. Write down every camera, door controller, heating panel, alarm and screen, who installed it and who supports it.
• Ask each supplier how they connect. If the answer is "we can get in from anywhere, any time", agree a better way: their own named account, switched on when you need them, and logged.
• Change every installer password. Where a device can't take a new password or an update any more, plan to replace it.
• Move the kit off your main network. A separate network segment keeps a hijacked camera away from your client files. It can also make Cyber Essentials easier to achieve, because a segment kept apart by a firewall can be scoped out with justification [6].

If something does go wrong, tell your insurer and report it to the National Cyber Security Centre (NCSC) [7].

Read more

Sources

1. [1]Newsweek, Cyberattacks target French blood banks after supermarkets hit, November 2026. https://www.newsweek.com/cyberattacks-target-french-blood-banks-refrigeration-supermarkets-12661343
2. [2]Al Jazeera, Hundreds of supermarkets in France hit by "unprecedented" cyberattack, 13 October 2026. https://www.aljazeera.com/news/2026/10/13/unprecedented-cyberattack-hits-french-supermarkets-causing-food-losses
3. [3]Al Jazeera, with Reuters, Very cold war: who's attacking Europe's supermarket freezers?, 3 November 2026. https://www.aljazeera.com/news/2026/11/3/very-cold-war-whos-attacking-europes-supermarket-freezers
4. [4]ITV News, UK meat processing firms hit amid fridge and freezer cyber attacks, 3 November 2026. https://www.itv.com/news/2026-11-03/uk-meat-processing-firms-hit-amid-fridge-and-freezer-cyber-attacks
5. [5]National Cyber Security Centre, Organisational use of enterprise connected devices, 10 May 2022. https://www.ncsc.gov.uk/report/organisational-use-of-enterprise-connected-devices
6. [6]National Cyber Security Centre, Cyber Essentials: requirements for IT infrastructure, v3.3, April 2026. https://www.ncsc.gov.uk/sites/default/files/2026-08/IT%20Requirements%20v3.3.pdf
7. [7]National Cyber Security Centre, Report a cyber incident, viewed 4 November 2026. https://report.ncsc.gov.uk/

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