Note, 5 November 2026

Supermarket freezers across Europe reported heating up, and where a safety limit should live

Starting overnight into Monday 2 November 2026, supermarkets in at least ten European countries reported freezers heating up, three weeks after a cyberattack hit hundreds of French supermarkets. No attacker has been formally identified, and online claims are not verified.

What happened

The French attack began on the night of 11 to 12 October, and more equipment was reported hit on 13 October (franceinfo). The second wave came overnight into Monday 2 November (The Guardian). The BBC counted at least ten countries on Monday; AFP and Reuters later counted at least eleven. Outlets differ on which countries were hit on Monday and which on Tuesday.

A Swedish store wrote that its freezers were hacked overnight and set to 50 °C (BBC, 2 November); its chain did not confirm a cyberattack (BBC, 3 November).

On 2 November a supplier to France's blood service, the EFS, was hit and cold-room controls at three sites were affected. The EFS says its own monitoring and alarm systems spotted the problem quickly, and no blood product was lost (EFS, in French).

What the reports describe

BleepingComputer reported that in France in October the attackers triggered a built-in defrost system. The head of one retail group said hackers put its cold units into defrost and raised them up to 50 °C (franceinfo). On 2 November a Belgian refrigeration company's chief told Belga its units' evaporators were switched to defrost mode (The Guardian). The EFS says defrost and temperature thresholds at its cold rooms were raised to very high temperatures.

The reports say the attackers forced the units into defrost and raised the temperature settings. We found no investigators' account of what was done.

Le Monde reported that in France the attackers also stretched the defrost from one hour to eight, so alarms would sound late; that is its report, not an investigators' finding (IBTimes UK).

A controller maker calls its supervisory unit "the brain of the system, coordinating data to and from the individual refrigeration and HVAC controllers, including temperature data for logging and alarms" (its own page).

What officials, makers and experts said

France's cyber agency, ANSSI, told the Senate on 21 October that basic security failings made the attack possible: equipment exposed directly to the internet, administered without particular protection, and weak passwords (BFM TV). On 3 November the head of the UK's National Cyber Security Centre said the French fridges were "connected directly to the internet with default passwords" (AP).

One maker of the affected controllers told franceinfo that most units hit were obsolete products that no longer get software or security updates.

A cybersecurity professor at the University of St. Gallen told AP: "A fridge doesn't look like a security risk, and that's exactly why attackers like it."

What is not known

Who did it. Claims have appeared online; we found none independently verified, and no formal attribution has been made (BBC, 4 November). We found no investigators' account of how the November attacks got in. Italy's government said the affected businesses were "mostly still equipped with obsolete security systems, with interfaces directly exposed to the internet and inadequate authentication mechanisms" (BBC, 3 November). This note is current to 5 November 2026.

Our take, as a hardware and software team

A limit that protects food belongs in the device, not in a setting anyone online can change: a defrost, for example, should stop at a fixed time and temperature that the network cannot raise. An alarm should not depend on the controller it watches; give it its own sensor, its own power and its own way out, so a hacked controller cannot silence it. And a controller that no longer gets updates should not face the public internet at all. This is our opinion; we do not know how any shop's equipment was set up.

About the film

Our own animation. The shop, freezer case and wall box are drawn after real commercial equipment, without brand marks; the display readings, sign-in screen and "end of support" sticker are illustrations. The map is Natural Earth data. The voice is synthetic.

Transcript

Supermarket freezers have a mode built to melt their own ice.

Hackers have turned it against the food.

Overnight into Monday, stores in at least ten countries, from Sweden to Ireland, reported freezers heating up.

One Swedish store said its freezers were set to fifty degrees. Celsius.

In France, Le Monde reported, attackers stretched the defrost from one hour to eight, so alarms would sound late.

In a supermarket, one small computer coordinates the fridges and freezers.

In France, many were old models that no longer got security updates.

Britain's cyber chief said the French fridges were connected directly to the internet, with default passwords.

France's own cyber agency put it down to basic security failures.

The same day, cold rooms at France's blood service were hit too. No blood product was lost.

"A fridge doesn't look like a security risk," one professor said, "and that's exactly why attackers like it."

Claims have appeared online. None is verified.

So who wants Europe's freezers warm? Follow for part two.

All notes