Military Commissary Refrigerators May Have Been Switched Into Defrost Mode

Refrigeration units at military commissaries in more than a dozen locations across the United States reportedly switched into defrost mode overnight, leaving food-storage areas unusually warm. The incidents were described in an investigation published by M. Elizabeth on the Substack newsletter Signal and Silence and reported by Boing Boing. The failures did not appear to be caused by power outages, according to the account. Instead, the units reportedly began their defrost cycles at multiple installations. In one deli case, the temperature was measured at 180º, according to the report. The affected food was therefore exposed to conditions far warmer than those expected of refrigerated storage. M. Elizabeth examined how commercial refrigeration systems are managed and found that commissary units—and their defrost settings in particular—can be controlled over a network from a centralized location. The investigation also pointed to two reports concerning security vulnerabilities in commercial refrigeration controllers: one involving Danfoss systems and another involving Copeland XWEB Pro controllers. Those findings prompted suspicion that the refrigeration problems might have been connected to unauthorized access. However, the available reporting does not establish that the units were hacked or identify who, if anyone, caused the defrost cycles. A Defense Department official told Military Times there had been “a possible refrigeration disruption” at some Defense Commissary Agency commissaries. The official also said it would be inappropriate to speculate about the cause of the outages. As a result, the incident remains unresolved: multiple commissary refrigeration systems reportedly entered defrost mode, and their network-controlled operation presents one possible avenue for investigation, but no confirmed explanation was provided.