French supermarket hack defrosts fridges across 400 stores

Attackers overrode temperature controls on legacy cooling software overnight, forcing major retail chains to dump tons of spoiled perishables.

Intruders hijacked refrigeration management software across hundreds of French supermarkets, forcing cooling units into an endless defrost cycle that spoiled perishable stock and triggered equipment shutdowns nationwide.¹²

The breach, carried out on the night of Oct. 11, hit roughly 400 retail locations across France, including outlets belonging to Coopérative U, Intermarché, Netto, Carrefour, Monoprix, and E.Leclerc.³⁴ Store managers arriving on Monday morning met waves of heat escaping from display units after temperatures inside freezers climbed as high as 50 degrees Celsius for more than six hours.⁴¹ In Le Haye, an Intermarché store reported that internal temperatures in some units reached 80 degrees Celsius, melting hardware and ruining stock.⁵

Retailers dumped tons of meat, dairy, vegetables, and frozen items across the country to prevent public health hazards.³⁴ Two stores in the Alsace region documented a combined 270,000 euros in initial inventory losses, while national trade figures indicated that overall losses could reach into the millions of euros.⁴²

Defrost cycles overridden remotely

Commercial refrigeration systems run automated defrost routines once or twice each day, warming cooling coils briefly to clear built-up ice before returning to subzero storage temperatures.²⁴ In this incident, perpetrators bypassed normal operating thresholds, instructing the systems to generate heat and remain active indefinitely.²⁴

The compromised installations relied on equipment controllers produced by the Danish engineering firm Danfoss.⁴⁵ Retailers use the central management software to monitor display cases and adjust store climate settings remotely.⁴ Dominique Schelcher, the chief executive of Coopérative U, said about 80 of his group's 2,000 locations suffered disruptions, adding that on-site staff intervened quickly in several stores to stabilise machinery before food degraded.⁵

Groupement Mousquetaires, which operates Intermarché and Netto, said approximately 150 of its supermarkets experienced direct interference, while staff disconnected another 100 locations from the internet to isolate their networks.³⁴ Carrefour confirmed disruptions in 80 of its 6,000 stores, and Monoprix reported issues across 5 percent of its commercial network.⁴³ E.Leclerc also acknowledged operational fallout across several of its regional locations.¹⁴

Vulnerabilities in older controllers

Danfoss stated that the incidents affected a limited selection of cooling installations and noted that the compromised units were legacy hardware models running outdated firmware.¹⁴ Danfoss spokesman Lars Grubak Lohff identified the affected product lines as older technologies, including the AK-SM 800 and AK-SC 355 controllers, which no longer receive software updates.³

Danfoss added that the company had long advised customers to keep supported installations updated with current firmware and migrate legacy hardware to modern platforms.¹³ Independent security researchers at Team82 had previously identified a hidden authentication vulnerability in Danfoss refrigeration controllers in August, warning that attackers could exploit the mechanism to manipulate cold storage operations remotely.²³

The Paris prosecutor's office opened a formal cybercrime inquiry into the campaign, describing it as a large-scale cyberattack targeting the refrigeration systems of major food retailers.⁴⁵ French national cybersecurity agency ANSSI took charge of the technical investigation alongside European security counterparts.¹ Schelcher termed the incident an unprecedented attack on the national food supply, noting that targeting distribution systems directly was intolerable.⁵¹

Disruption spreads across borders

Retail networks outside France experienced concurrent technical problems. Supermarket operators in Belgium, Luxembourg, and the Netherlands recorded operational anomalies over the same weekend, with Dutch operator Ahold Delhaize disconnecting store cooling systems to protect physical assets.¹²

Government authorities had already heightened commercial monitoring following state warnings regarding industrial sabotage against European critical infrastructure. French President Emmanuel Macron instructed ministers in September to draft protection frameworks guarding vital logistical supply chains and infrastructure against hostile cyber operations.³⁵ European Union Food and Agriculture Commissioner Christophe Hansen said the targeting of food logistics demonstrated that food security requires renewed defensive attention across every level of distribution.¹⁴

Save this story

The record

24 sentences trace to 5 sources.

All 5Documents 1Records 0Reporting 4People 0

1. 1 DW Deutsche Welle Third-party reporting · dw.com · 12 Oct 2026 French supermarkets targeted by massive defrost cyberattack See the source
2. 2 YN Yahoo News Third-party reporting · qz.com · 12 Oct 2026 Cyberattack disables refrigeration at French supermarkets See the source
3. 3 TS The Straits Times Third-party reporting · straitstimes.com · 12 Oct 2026 Hackers hit French supermarkets in attack disabling fridges, forcing stores to discard food See the source
4. 4 BN BBC News Third-party reporting · bbc.co.uk · 12 Oct 2026 Fridges in French supermarkets hit by cyber attack See the source
5. 5 FT Financial Times Document · ft.com · 13 Oct 2026 Cyber attack on French supermarket fridges raises alarm over food security See the source