Hackers Heat French Supermarket Fridges to 50°C

Hackers took control of refrigeration systems at hundreds of French supermarkets overnight on October 11–12. Les Mousquetaires, which owns Intermarché and Netto, said attackers activated defrosting and raised temperatures to as much as 50°C, according to The Hacker News.

The attack reached several retail groups, including Carrefour, Coopérative U, Monoprix, and E.Leclerc. Carrefour reported 80 affected supermarkets, while Monoprix reported about 30. Counts for Intermarché and Netto differed across reports, so a precise nationwide total is not established.

The damage also varied by store. Intermarché said affected locations discarded the products concerned. Coopérative U reported attacks on 80 stores, but its president said most preserved the cold chain through quick intervention by staff and refrigeration contractors.

The systems use Danfoss controllers to manage refrigeration equipment. On October 12, France's CERT-FR confirmed numerous compromises affecting the AK-SM and AK-SC series. Neither the agency nor Danfoss has publicly identified the attackers or how they gained entry.

Danfoss said most affected units were older products without ongoing security updates, including the AK-SM 800 and AK-SC 355. The company also told Cooling Post that some newer AK-SM 800A units running outdated firmware suffered compromises. Previously disclosed vulnerabilities in newer controllers have not been linked to this attack.

CERT-FR instructed operators to disconnect the controllers or restrict network access. For suspected compromises, its recovery procedure includes a factory reset, available security patches, credential rotation, account checks, and complete reconfiguration. The agency specifically warned against exposing management interfaces to the public internet.