Supermarkets across Sweden, Belgium, Ireland, Luxembourg, the Netherlands, and Estonia reported cooling problems overnight into Monday, November 2. Suspected cyberattacks changed refrigerator and freezer settings, causing temperatures to rise. Some Swedish freezers reached 122 degrees Fahrenheit, and stores had to throw away spoiled food.
The disruption affected 15 Carrefour stores in Belgium and 13 SuperValu stores in Ireland. Belgian prosecutors opened an investigation, but those responsible have not been identified. Sabcobel, a Belgian refrigeration company, said attackers switched equipment into defrost mode, a setting normally used to melt ice.
Internet connections allow technicians to check faults and adjust supermarket cooling systems without visiting each store. However, these connections can also give attackers a way to change temperatures or turn off alarms. Cybersecurity company Forescout recommends removing refrigeration controls from the open internet and allowing technicians to connect through secure tools. It also recommends replacing equipment that no longer receives security updates.
In a separate series of attacks, hundreds of French supermarkets experienced similar disruption in October. Some equipment involved in France and the latest incidents used technology from Danfoss. Although the incidents share similarities, investigators have not established whether the same security weaknesses or attackers were involved.
