Hundreds of French supermarkets opened to find the freezers at 50 degrees

Staff arrived on the morning of 12 October to freezer cabinets reading 50 degrees Celsius and aisles of food that had to go straight in the bin.

Overnight, somebody reached into the refrigeration controllers at between 250 and 350 French supermarkets and triggered the defrost cycle that every such system has built in. Intermarché and Netto counted at least 300 affected stores, Coopérative U around 80, Carrefour roughly 80 more, Monoprix about 30, with several E.Leclerc sites as well. The Paris prosecutor's office says some equipment began to catch fire. The head of Les Mousquetaires put the losses in the tens of millions of euros. There was no ransom note, no demand, no outage at the tills. The damage was done entirely to things that were supposed to stay cold.

The targets were Danfoss controllers, mostly the older AK-SM 800 and AK-SC 355 models, along with some current AK-SM 800A units running outdated firmware. Danfoss says most of the affected hardware are older products that no longer receive security updates. Researchers at Claroty had already found thousands of those management interfaces sitting on the public internet, which is the part worth sitting with: industrial kit, reachable from anywhere, running software whose last patch shipped years ago.

Your house runs the same arrangement at a smaller scale. The router from your provider, the camera you set up in 2021, the doorbell, the network drive in the cupboard. Each one is a small computer with firmware, and most of them will never ask you to update anything. Check the admin page of each for a firmware update, change any password you never changed, and switch off remote access you do not use. Tendvane's network scan shows everything currently on your network, which tends to be the fastest way to find the device you had forgotten about.