The Pentagon is investigating a possible hacker attack on freezers at more than 6 military stores on US bases in August, sources familiar with the inquiry said. US military investigators are also checking whether it is linked to the cyberattack on cooling systems in hundreds of French supermarkets about two months later.
So far there is no evidence that the two cases are connected, or that the damage at the military stores was caused by hackers at all.
The Pentagon confirmed only that a unit of US Cyber Command, the military's cyber force, is working closely with partners in other government agencies and law enforcement. The department does not comment on ongoing investigations for security reasons. It is not clear how far the inquiry has got, whether investigators know what happened, or who is behind the damage.
The cybercrime unit of the US Army Criminal Investigation Division is also involved. It is working with French law enforcement on the cooling system outages in Europe.
In France, hackers took over the fridges in hundreds of supermarkets overnight. They did not switch them off. They raised the temperature above 50°C, and the food spoiled. Some systems got so hot that fires broke out.
Eighty Carrefour stores, about 20 Monoprix stores and 150 Intermarché stores were hit. Intermarché and E.Leclerc put the damage to stock at about €270,000. One supermarket owner thinks the total cost of the attack across France could reach tens of millions of euros. The Paris prosecutor's office called the attack "large-scale".
Similar damage has been reported elsewhere in Europe. In Estonia on Monday, hackers broke into the computer that runs the cooling system of a Selver supermarket and set the freezer to 50°C above zero. A quick response prevented any damage. In the US, a similar temperature rise also happened at Fort Huachuca in Arizona.
Prof Christopher White, who teaches national security at Virginia Commonwealth University, says it would be naive not to suspect a link. He says fridges give an attacker a direct route to damage that cannot be undone, because spoiled food and goods cannot be returned. "This is just throwing away euros and dollars," White says.
Nadia Kostyuk of Carnegie Mellon University is surprised it took so long for such devices to become targets. Cybersecurity experts say it was only a matter of time before hackers turned to household and industrial appliances like fridges. Artificial intelligence is making attacks more complex, and the more devices are connected to the internet, the more targets there are.
Sabotage of cold storage over the internet has long been among the worst-case scenarios, alongside cutting power or water, because freezers are key to the supply of fresh food. Napoleon Bonaparte, whose army was defeated in Russia after its supply lines were stretched too far, is said to have remarked that "an army marches on its stomach".
Gregory Winger of the University of Maryland said that actors from Russia, China, Iran and North Korea often carry out cyberattacks that look random but are linked to each other. He says that whether or not the same hackers are behind both cases, the US is starting a joint inquiry with France for strategic reasons, mainly to share information. Winger believes every future military operation will now have a cyber element.
Allies are building partnerships to spot hacking methods and share information about them. NATO's cyber security centre is at the Supreme Headquarters Allied Powers Europe in Mons, Belgium. Major attacks can trigger NATO's Article 5 on collective defence, under which a threat to one member is a threat to all.
The number of cyberattacks has been rising for two decades, especially against firms and government bodies. In September alone there were more than 10 major attacks, according to the Center for Strategic and International Studies. Cybersecurity Ventures estimates that cybercrime will cost the world economy $10.8 trillion this year, up from $3 trillion in 2015.