Perhaps Connecting Fridges to the Internet Was a Bad Idea

Bags of frozen blueberries and Swedish meatballs, packets of waffles and pizzas, and tub after tub of ice cream: all melted, floppy, spoiled, and stinking. This has been the scene at grocery stores across Europe after their fridges and freezers have been hacked.

Last month, employees at hundreds of supermarkets in France came into work to find they had to trash millions of dollars’ worth of food. The machines were not simply deactivated; they had been remotely hijacked and reprogrammed to hit temperatures as high as 122 degrees Fahrenheit. Last Monday, grocery outlets in at least seven more countries, including Estonia, Belgium, and Sweden, experienced a near-identical incident. The same day, freezers at the French national blood bank were also hacked (though staffers were able to intervene before any samples were corrupted). Depending on who you talk with, America is either next or has already been hit: In August, the Pentagon quietly revealed that freezers at commissaries on several U.S. military bases had malfunctioned in a suspected attack.

No one has claimed responsibility for any of these exploits, and it’s not even clear whether they are connected. The hackers seemingly didn’t have a goal besides sowing chaos and wasting an enormous amount of food. Perhaps the most surprising aspect of these widespread fridge attacks is that they haven’t happened sooner. For hackers, these appliances make perfect targets.

The basic problem is that many fridges and freezers are now connected to the internet. “The attacks are very simple,” Nadiya Kostyuk, a cybersecurity researcher at Carnegie Mellon University, told me. Each unit has a microcontroller that is connected to the local network, so even someone sitting at a computer thousands of miles away can theoretically access it. These devices are typically password-protected, but they still tend to be pretty easy to crack, Kostyuk explained. “Usually it’s done by brute force,” which is to say the devices are spammed with password after password until one works. Some of the recent attacks were made simpler because usernames and passwords had never been changed from the manufacturer’s defaults. Once the hackers remotely broke into a system, they were able to take control of a heating element that can be periodically switched on to prevent frost from building up on the evaporator coils, which stops the freezer from working as effectively. Instructed to run repeatedly, that heating element has proved capable of cooking perishable food.

For a home fridge, the benefits—a touchscreen that can show family photos, an interior camera so you can see what you already have while you’re at the grocery store—may not outweigh the security risks. In the aftermath of the recent attacks, people have assumed the same is true for industrial fridges: Why on earth does a supermarket fridge need to be online? But for the millions of supermarket chill cabinets, refrigerated trucks and shipping containers, and gigantic cold-storage warehouses that our food sits in on its way from farm to table, the calculus is quite different.

Logistics companies are often required to demonstrate that food has stayed within a narrow temperature range while in their custody; the ability for a freezer to broadcast an alert if its temperature deviates from a set point at 2 a.m. is an extremely useful feature. Refrigeration units are always on—they have to run 24/7 by design—and a lot of today’s smartest devices provide the diagnostics that allow companies to perform predictive maintenance to preempt any potential issues. “The risk of loss is so high if the unit goes down,” Chris Gaffney, a supply-chain expert at Georgia Tech who previously ran logistics for Coca-Cola, told me.

The food that our fridges are protecting is extremely fragile; the machines themselves are quite complex; and qualified technicians are in short supply. A refrigerated warehouse, let alone a supermarket, won’t have a person with that kind of specialist skill set on-site, Gaffney said. But when connected to the internet, a scattered portfolio of freezers can be managed and sometimes even fixed remotely. And, as politicians push legislation to make food traceable, the entire supply chain is being digitized. “There are a lot of positives that come with that—ways to increase our food security and understanding where food is coming from,” Sara Stickler, the president of the Global Cold Chain Alliance, an industry trade group, told me. “But with digitization, there also comes risks.”

The food business isn’t like banking, where online security is central to a company’s value proposition. In perishable logistics, where the mission is keeping food cold, warehouse operators and grocery stores have not typically seen the value in spending extra on cybersecurity. “Margins are tough,” Gaffney said. When it comes to adopting sophisticated new technology, he told me, “logistics is a laggard, and within logistics, cold is a laggard.”

The genius and horror of hacking refrigeration is that although the cold chain is essential infrastructure, it’s not treated as such. As I quickly learned while writing Frostbite, my recent book on the topic, almost no one has a complete picture of refrigeration’s scope and scale. Nearly three-quarters of everything on the American plate passes through the cold chain on its way to our tables. Thousands of chilled warehouses, refrigerated containers and trucks, meat lockers, and banana-ripening rooms are located out of sight, underground, at ports, near freeway intersections or cattle ranches: Added together, these pockets of artificial winter form the invisible backbone of our food system.

Meanwhile, refrigeration is somehow different from other crucial infrastructure—water-treatment plants, say, or power stations—where the public may be ignorant, but at least industry members and government officials are on top of how many facilities we have and where they are. As supermarket shelves emptied during the early days of COVID, one industry expert told me that he received a frantic call from a senior official in the government asking how many refrigerated trucks and warehouses the country’s food supply depended on.

If there is a silver lining to these attacks, it is that they could serve as a wake-up call. “With these cyberattacks, it totally redefines what ‘critical infrastructure’ is,” Kostyuk said. After all, cyberattacks are not the only threat facing our food-supply chain: Dozens of supermarket refrigerators across the U.K. failed this summer during a heat wave that pushed them beyond their limits, and severe-weather-induced blackouts are a constant threat. Whether the culprit is a hacker or the weather, the outcome remains the same. Get used to seeing more empty supermarket shelves.