Hackers have repeatedly broken into the refrigeration systems of supermarkets across Europe, raising temperatures, spoiling food and even reaching a French blood bank, and US agencies have now warned that cold-chain systems worldwide are at risk. The first wave struck hundreds of stores in France overnight on 11-12 October. A second wave on 2 November disrupted refrigeration at more than 100 stores and businesses across at least seven European Union countries, with Germany, Romania and the UK also reporting incidents.

The attackers targeted electronic temperature controllers used in retail grocery stores and cold storage facilities, forcing cooling units into heating and defrost cycles. In France, cold storage units at three sites run by the French Blood Establishment were also hit, although the service said it detected the activity in time to rescue blood samples. Belgian refrigeration firm Sabcobel said attackers had switched evaporators into defrost mode, causing temperatures to rise. Equipment supplier Danfoss said some targeted systems in the Netherlands were still connected to unsecured networks and protected only by default passwords.

US agencies issue a joint warning

On 5 November, the US Cybersecurity and Infrastructure Security Agency, the FBI, the Department of Health and Human Services, the Department of Agriculture and the Department of Transportation published a joint fact sheet warning that malicious actors are targeting industrial refrigeration and cold-chain monitoring systems worldwide. The agencies said attackers may exploit unpatched or internet-accessible devices to manipulate temperature settings, disrupt temperature visibility and create equipment and fire hazards. No group has been confirmed as responsible, although two pro-Russian hacking groups have claimed the attacks in online posts. Operators are urged to take controllers off the public internet, change default passwords and update firmware.