When supermarket managers across France arrived at work on Monday morning, they were met not by the familiar chill of the freezer aisles, but by sudden waves of hot air. A coordinated cyberattack had compromised cooling systems in roughly 400 supermarkets, reportedly causing some refrigeration units to reach 50°C (120°F) overnight and spoiling millions of euros worth of fresh and frozen food.
The attack compromised software provided by Danish engineering firm Danfoss, which retailers use to monitor and regulate refrigeration units remotely. While commercial freezers typically undergo brief overnight defrost cycles where temperatures rise slightly, hackers instructed the systems to heat up and stay hot for hours. Several major retail chains—including Coopérative U, Intermarché, Carrefour, and Monoprix—reported disruptions. In some locations, the extreme temperatures sparked small fires, and one freezer in an ice cream aisle was photographed showing a reading of 26.5°C.
Danfoss explained that the incident affected older models whose security software could no longer be updated against identified vulnerabilities, adding that it had long advised companies to keep supported systems updated. As managers discovered the damage, retailers rushed to disconnect another 100 stores from the internet to prevent further breaches and disposed of all affected stock to avoid health hazards. In the Alsace region alone, two stores estimated their combined losses at €270,000.
The Paris prosecutor's office has launched a formal cybercrime investigation into what it described as a large-scale attack against major food retailers. European Food Commissioner Christophe Hansen condemned the incident on social media, warning that the deliberate targeting of cold storage infrastructure shows how vital digital security has become to protecting essential food supplies.