The Pentagon believes a spate of freezer malfunctions that spoiled food at military bases across the United States in August may have been the work of hackers, according to a new report.

The malfunctions affected at least six commissaries in late August, according to a Reuters review. Commissaries are stores on military bases where service members buy their food.

In at least one of the cases, the cooling units’ temperatures were cranked up overnight, leading to mounds of wilted or melted food in the morning.

“Trust us when we say it was ‘spoiled,'” Fort Huachuca in Arizona said in a Facebook post on Aug. 26 after its freezer “went into defrost mode where it heated up all the food.”

Military investigators were in touch with their French counterparts about a similar cyberattack on commercial freezers that disrupted supermarkets there earlier this month.

The US Department of the Army Criminal Investigation Division said its Cyber Field Office was involved in the investigation and that it was working with French law enforcement to better understand “the refrigeration outages in Europe.”

When asked about the investigation by Reuters, the Pentagon said that a unit of Cyber Command – the military’s cyber force – was “working in close coordination with interagency and law enforcement partners.”

The Pentagon seemingly has not reached a conclusion about what happened or who might be responsible. The spate of rogue freezer behavior and the possibility of cybersabotage were first reported on August 28 by a blog called Signal and Silence.

French freezers attacked

If the military base malfunctions are confirmed to be a cyberattack, it would be yet another illustration of how hackers can target vulnerable critical infrastructure, including cold storage.

In France, a freezer cyberattack overrode temperature controls on commercial cooling units in more than 350 establishments. Supermarkets’ frozen food aisles were cleared of spoiled merchandise, leading to dramatic scenes.

The French hack involved cranking the temperature inside the units up rather than merely knocking them offline, similar to what happened in Fort Huachuca in Arizona.

Some French refrigeration units had the temperature turned up so high that they caught fire.

Costly damage

The French attack’s total costs could add up to tens of millions of euros nationwide, one supermarket owner estimated earlier this month. The French cyberattack appeared to have been easy to pull off, experts previously told Reuters.

The Danish firm Danfoss, whose controllers ran many of the stricken units, said that many of the devices were obsolete or were running outdated firmware, which could have made it easy for hackers to break in.

Reuters could not establish whether Danfoss or any other brand of freezer controller were in use at the affected US bases and Danfoss did not return its messages seeking comment.

Refrigeration plays a critical role in the distribution of fresh food. The sabotage of cold storage facilities via the internet has long been seen as a nightmare scenario, alongside the loss of electricity or water plants.

Earlier this year, the Global Food Safety Initiative, urged food safety professionals and IT leaders to work together to ensure “robust cybersecurity” for refrigeration technology, stating that “a hacked cooling system is just as dangerous as a broken one.”

Previous refrigeration hacks

Hackers have sabotaged fridges and freezers in the United States and elsewhere. In 2022, hackers either targeted or broke into supermarkets in Russia and Israel that were using obsolete versions of its cold storage controllers, Danfoss previously said.

In December 2025, federal prosecutors in Los Angeles accused a Ukrainian woman of being part of a hacker group that knocked out refrigeration at a meatpacking facility in 2024, ruining more than 2,000 pounds of meat.

Bill Moore, chief executive of industrial cybersecurity firm Xona Systems, said that controllers that were initially conceived as isolated interfaces to be serviced by an in-person technician were increasingly being connected to the internet, which was the main problem.

Concerns about online exposure were not unique to cooling systems but they could have particularly serious consequences there, he said.

“It can definitely disrupt the supply chain for food,” he said.