US agencies warn of attacks on refrigeration systems

On 5 November 2026, the United States Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), and three other federal agencies issued a warning urging operators to secure industrial refrigeration and cold-chain monitoring systems after cyberattacks on supermarket refrigeration across Europe.

The alert follows France’s national blood service confirming that monitoring and control systems at three cold-storage sites were affected, with staff intervening before any blood products or samples were compromised.

Danfoss, the refrigeration equipment supplier, told Dutch customers to disconnect systems from the public internet and reconnect only through a secure network after attacks began in France on 13 October. The company said most stores followed the guidance; by 2 November similar attacks reached the Netherlands, but major supermarket chains were reportedly unaffected.

An official spokesperson noted that affected systems remained accessible via unsecured connections and used default passwords, warning that the incidents could have been prevented with the advised precautions. CISA and partners warned that attackers may exploit authentication bypass flaws, code-injection vulnerabilities, or weak configurations in refrigeration controllers, potentially allowing attackers to change temperatures or force equipment into continuous heating or defrost cycles.

To reduce risk, the agencies recommend keeping control panels off the public internet, isolating operational equipment from business networks, changing default passwords, using strong authentication, patching firmware, replacing unsupported devices, and setting safe operating limits and alerts for temperature changes outside those limits.