Hackers raise supermarket fridge temperatures to 50°C in massive cyberattack

Hackers remotely raised refrigerator temperatures to as high as 50°C at hundreds of supermarkets across France, spoiling fresh and frozen food and prompting an investigation into the cyberattack.

The attack, which began overnight on Sunday, October 11, affected major supermarket chains including Intermarché, Coopérative U, Carrefour and E. Leclerc.

According to Reuters, hackers took control of refrigeration systems and triggered automatic defrost cycles, raising temperatures and forcing stores to discard food that could no longer be safely sold.

At least 300 Intermarché and Netto stores, more than 100 Coopérative U outlets, and 80 Carrefour supermarkets were affected, according to retailer figures.

Paris prosecutors said the attack had caused food losses and fires at some locations. Investigators have opened an inquiry to determine the extent of the damage and identify those responsible.

How hackers targeted the refrigerators

The attack reportedly targeted refrigeration controllers supplied by Danish manufacturer Danfoss, which allow supermarket operators to monitor and adjust temperatures remotely.

Danfoss said its AK-SM800 and AK-SC355 refrigeration control systems were among those affected.

Most of the compromised equipment consisted of older models that no longer receive software or security updates, the company said. One affected AK-SM800 version was running outdated firmware.

The company said it had previously advised customers to upgrade older systems.

Cybersecurity specialists have identified vulnerabilities in some Danfoss refrigeration controllers, but investigators have not confirmed which security weakness the latest attack exploited.

Supermarkets forced to throw away food

The cyberattack left refrigerated display units and freezers unusable at several stores.

Intermarché said affected branches had to remove fresh and frozen products, causing substantial food waste and financial losses.

Some refrigeration units reportedly reached 50°C, while a store in France recorded temperatures as high as 80°C, Le Monde reported.

The total financial damage has not been established.

Coopérative U chief executive Dominique Schelcher described the attack as unprecedented and said teams were working with refrigeration specialists to restore affected systems.

Authorities investigate

French Prime Minister Sébastien Lecornu instructed the country’s national cybersecurity agency, ANSSI, to investigate the attack.

French authorities are also coordinating with European counterparts, concerned that similar refrigeration systems in other countries could be vulnerable.

Authorities have not identified the attackers or how they gained access to the systems.