Hackers broke into the refrigeration systems of hundreds of French supermarkets on Sunday night. Stores had to throw out meat, frozen goods and vegetables.
About 150 Intermarché stores were hit, a spokesman for owner Groupement Mousquetaires told Bloomberg. The attackers set the cooling systems to defrost.
Fridges and freezers heated to 50°C for around six hours, the spokesman said.
Super U and Leclerc also hit
Coopérative U was also targeted, chief executive Dominique Schelcher said on X. Fewer than 100 of its stores were affected, Agence France-Presse reported.
Some Leclerc stores were hit too, French broadcaster BFM reported. Leclerc did not immediately respond to Bloomberg’s request for comment.
A known weak spot
Mousquetaires said the systems were managed by Danfoss, the Danish refrigeration group. It said it was up to the supplier to file a complaint with the authorities.
In August, Claroty’s Team82 researchers flagged flaws in Danfoss controllers used in supermarkets and cold stores. They found a hidden login, based on a daily code, that could give an attacker admin access.
Team82 said Danfoss had released a firmware fix. It also found thousands of the controllers reachable from the internet.
It is not yet known whether those flaws were used on Sunday. Neither the retailers nor Danfoss have said how the attackers got in.
The incident adds to a run of attacks that halt operations rather than steal data. The JLR hack and the Boston Scientific breach both disrupted physical production and shipping.
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