Dozens of supermarkets have been hit by cyberattacks across Sweden and Belgium, which caused the temperature of freezers to rise sharply overnight. 

It comes a month after hackers seized control of cooling units at hundreds of French supermarkets in a large-scale attack, causing food losses and fires.  

One Swedish store on Monday said on social media that the temperature of its refrigerators and freezers had been set to 50 degrees Celsius, similar to the attack in France.

‘We are aware that a limited number of stores were affected by an incident overnight, which impacted their refrigeration and freezer systems,’ a spokesperson at privately held ICA said in an email.

Privately held grocery retail group Coop told daily Aftonbladet that six of its stores had been affected by similar incidents.

Coop did not immediately respond to a request for comment.

Last month’s incident in France is being investigated by the country’s National Cybersecurity Agency. 

France has also been coordinating with European counterparts because other countries could also be affected. 

An employee cleans refrigerators at an ICA Baronen store on Odengatan in Stockholm, Sweden, 02 November 2026, after the temperatures of freezers at several Swedish grocery stores rose sharply overnight

Employee throw away bags of spoiled refrigerated food outside an ICA suparmarket on Odengatan in Stockholm, on November 2

Carrefour said 80 of its supermarkets were hit, while Monoprix, which operates about 490 ​stores in France, said 5 per cent of its stores were affected.

Les Mousquetaires, owner of retailer Intermarché, said fridges at around 150 of its ⁠stores were heated up to 50 C for six hours overnight. 

A spokesperson said all affected food had been discarded to eliminate health risks.

Supermarket staff were seen throwing cartfuls of defrosted frozen foods into a giant trash container, with molten ice cream sloshing out of broken tubs on the street.

There was no immediate estimate of industry-wide losses, but Intermarché CEO Thierry Cotillard told BFM TV at the time the ‘unprecedented’ attack would represent losses amounting to ‘tens ​of millions of euros nationwide in a single day.’ 

Supermarket cold aisles are typically run by control panels that manage an entire store’s fridges and freezers and can be accessed over the internet, which lets maintenance companies adjust them from anywhere.

The source ‌close to the investigation said ANSSI had identified a vulnerability in software supplied by Danish company Danfoss.

Danfoss said it was ‘aware of incidents in France affecting a limited number of refrigeration management systems’.

The affected units ‘were running outdated firmware’, Danfoss said, adding that it had ‘long advised customers to keep supported systems updated with the latest firmware and to migrate legacy systems to current-generation solutions’.

The ​attacks resemble disruptions reported at about a ⁠dozen US military commissaries in late August that led to food losses after fridges were affected.

In a statement, French retail association Fédération du Commerce et de la Distribution called for ‘full transparency’ from Danfoss about the incident. 

It said supermarkets aimed to protect consumers and return to ​normal operations as soon as possible. The FCD said some impacted stores were already back up and running.