Overnight between October 11 and 12, hackers took control of the refrigeration systems at several hundred French supermarkets. Intermarché, Netto, Coopérative U, Carrefour Market, Monoprix, Leclerc and Super U are among the chains affected. According to several French outlets cited by the specialist site BleepingComputer, somewhere between 250 and 350 stores were hit, though none of the chains has published an exact list.
The method is well documented. Attackers targeted refrigeration controllers running outdated versions of Danfoss software, then triggered the units’ built-in automatic defrost function. The result: temperatures in some display cases climbed as high as 50°C (122°F), forcing staff to rush and clear out fridges and cold rooms. Industrial cybersecurity firm Claroty had actually flagged two critical flaws back in August 2025 (tracked as CVE-2025-41450 and CVE-2025-41451) in Danfoss’s AK-SM 8xxA monitoring platform, which allow remote takeover. Whether this attack used those specific flaws hasn’t been confirmed.
For the chains, the bill looks steep: financial losses on one side, tons of discarded yogurt, meat and seafood platters on the other. Coopérative U’s CEO played down the scale of the damage across his network, while teams there were still working with refrigeration specialists to get things back to normal. Paris prosecutors have opened an investigation, partly to establish whether there’s a link between the attack and fires reported at some stores; authorities haven’t confirmed anything on that front yet.
One detail stands out more than the rest: the failure traced back to a flaw that was already more than a year old, sitting in software nobody had bothered to update. For the cold chain, that quiet backbone of every kitchen, it’s exactly this kind of technical neglect that ends up emptying entire aisles.