US Army investigators are working with French authorities to help understand a spate of freezer failures that occurred across military bases in the United States in August, following a spate of similar incidents affecting hundreds of supermarket refrigeration units across France in October.

A spokesperson for the US Army Criminal Investigation Division said the agency is working with other investigators to understand the failures on military bases.

Army investigators are also working with French law enforcement to understand the outages in that country, the spokesperson said.

Hacking probe

The division said its Cyber Field Office was involved in the investigation, indicating the US incidents may be suspected of being caused by hackers, as was the case in France.

Six military installations in the United States have publicly acknowledged simultaneous freezer failures in commissaries, with at least one saying the units had been raised to elevated temperatures, spoiling food, similar to what occurred in the French hacks.

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

The hacks in France affected more than 350 refrigeration units, with some reaching temperatures so high that they caught fire.

Security failures

France’s cyber agency ANSSI said the hacks were carried out by exploiting basic security failures, such as weak passwords and a lack of rudimentary cyber defences.

Industrial cyber-security firm Xona Systems said many of the controllers involved were initially conceived as isolated interfaces that would be serviced in-person by a technician, but were increasingly being connected to the internet, creating security exposures for which they’d never been intended.

Such incidents highlight concerns around “hybrid attacks” that could disrupt critical physical infrastructure.