Turning Up the Heat: Inside the Attacks on Europe’s Refrigeration System

Threat actors — likely pro-Russian hacktivist groups — exploited suspected default credentials and unpatched software to gain control of industrial refrigeration controllers across European supermarkets and medical facilities, switching them to defrost mode and causing widespread food spoilage and potential harm to temperature-sensitive medical supplies. This attack highlights a chronic failure in operational technology (OT) security: internet-exposed industrial control systems are routinely left with factory-default passwords and unpatched firmware, making them trivial targets. The consequences extend well beyond IT disruption — compromised OT systems can directly harm public health and critical supply chains. As hacktivists increasingly target physical infrastructure to cause visible societal impact, the security baseline for OT environments must rise significantly.