French supermarket cyber attack spoils millions in food as hackers sabotage refrigeration

On Monday morning, store managers across France arrived at work to find their supermarkets transformed into ovens. Hundreds of refrigeration units had spent the night heating up instead of cooling down, their contents spoiling in the warmth. By the time staff discovered what had happened, millions of euros worth of fresh and frozen food had been destroyed in what French prosecutors would call a large-scale cyber-attack targeting the nation's food retail infrastructure.

The hackers had gained control of refrigeration software provided by Danfoss, a Danish engineering firm whose systems manage cold units remotely across supermarket chains. Rather than allowing the normal overnight defrost cycle—a brief, controlled temperature rise—the attackers forced the units to heat up and remain hot. In some cases, freezers reached 50 degrees Celsius, roughly 120 Fahrenheit, for six hours straight. Store managers walking in Monday morning were hit by waves of hot air. In a few locations, small fires broke out.

The scope of the breach was staggering. More than 100 supermarkets belonging to Coopérative U were hit. Intermarché and its Netto brand saw 180 stores affected, with another 100 hastily disconnected from the internet to prevent further damage. Carrefour, Monoprix, and E.Leclerc were also targeted. Across France, roughly 400 stores out of approximately 15,000 total supermarkets fell victim to the attack. Carrefour reported compromised fridges in 80 of its 6,000 locations. Monoprix said about 5 percent of its 400-plus stores were hit. In the Alsace region alone, two supermarkets reported combined losses of €270,000—roughly £228,000—suggesting the nationwide total would run into the millions.

The vulnerability that made the attack possible was not new. Danfoss acknowledged that the affected refrigeration units were older models whose security software could not be updated to protect against a known risk the company had identified. The firm stated it had long advised businesses to maintain supported systems and keep their software current, but many retailers had not done so. When the attack came, those outdated systems had no defense.

Staff at affected stores faced an immediate crisis. All food that had been exposed to the extreme heat had to be removed from sale. Intermarché threw away every item in the compromised units to avoid health risks. Managers and refrigeration specialists worked through Monday afternoon to restock shelves and restore service. Dominique Schelcher, chief executive of Coopérative U, called the attack "extremely serious and unprecedented" and said staff were "fully mobilised" to fix the damage. He demanded an investigation and condemned the targeting of equipment essential to France's food supply as "unacceptable."

The incident caught the attention of European officials. Christophe Hansen, the European Food Commissioner, posted on X that the attack underscored a troubling reality: food security now required urgent attention at every level. He noted that the weaponization of food had become real. French prosecutors opened a dedicated cyber-crime investigation, treating the breach as a deliberate assault on critical infrastructure rather than a routine security incident.

The attack exposed a fragile link in the food supply chain. Supermarkets depend on remote management systems to keep their inventory safe, but many had not invested in updating the security of those systems. Danfoss had warned customers to patch their software, but older equipment simply could not be updated. When hackers found that gap, they exploited it with precision, targeting not data but the physical systems that keep food fresh. The result was not stolen information but destroyed goods, empty shelves, and a stark reminder that critical infrastructure—even something as mundane as a supermarket freezer—can be weaponized.