Paris prosecutors have opened a probe into the incident, according to various news outlets.

Hundreds of French supermarkets fell victim to a cyberattack on Sunday (11 October) after hackers turned up the temperatures of remotely controlled refrigerators as high as 50 degree Celsius overnight, leading to food waste and fires.

Around 150 to 200 Intermarché stores, owned by Groupement Mousquetaires, were affected in the attack, as well as 80 Coopérative U outlets and around 80 Carrefour supermarkets, according to various reports.

France’s largest supermarket chain, E Leclerc, was also reportedly attacked. Meanwhile, Monoprix said about 5pc of its roughly 490 stores were hit.

Hackers reportedly accessed cooling systems and set them to defrost, causing refrigeration systems to overheat for around six hours.

The Paris prosecutor’s office confirmed the attacks with news outlets and said that it has opened an investigation into the “large-scale” cyberattack affecting the cold rooms of several major food retail chains across France.

The probe aims to identify victims and establish a link with the damage they have reported in relation to food waste and fires.

Targeting essential equipment such as food refrigerators is “extremely serious and unprecedented”, said Coopérative U CEO Dominique Schelcher in a translated post on X yesterday (12 October).

“Our teams are fully mobilised, in contact with refrigeration technicians, to restore the situation as quickly as possible. An investigation will be conducted to shed full light on this attack.”

Mousquetaires said its cooling systems are managed by Danish refrigeration firm Danfoss, which said that it is working with its customers to resolve the issue. A spokesperson from the company told Bloomberg that a majority of the affected systems are old and no longer receive updates.

“Danfoss has long advised customers to keep supported systems updated with the latest firmware and to migrate legacy systems to current-generation solutions,” he told the publication.

Reports also suggest that France’s cybersecurity agency had already identified vulnerabilities in the “software supplied by a Danish company”. The agency is in contact with its European counterparts as other countries may also be affected, sources said told the Journal.

The attack comes after the UK’s National Audit Office named cyberattacks as one of the major threats facing the country’s food supply chain just last month.

“Expect attackers to pay increasing attention to this intersection between IT, operational technology and connected physical infrastructure,” said Forrester senior analyst Madelein van der Hout.

“Remote management expands the attack surface. Organisations increasingly depend on suppliers and service providers to monitor and manage physical equipment remotely.

“That connectivity creates efficiency, but it also creates paths into environments that organisations may not monitor or secure as closely as their traditional IT estate.”

In recent weeks, a barrage of cyberattacks have threatened to disrupt public and private services across Japan, Spain, Norway, Denmark, Germany and Italy.

While these attacks haven’t been explicitly linked to AI, the technology has added significant power behind bad actors who can now carry out large scale hacks with comparatively minimal resources.

Earlier this month, Anthropic expanded its cyber defence programme, which includes Project Glasswing, a joint project with global organisations and public bodies to address their cyber vulnerabilities.

Initiatives such as Project Glasswing can make an important contribution, added van der Hout, “but Anthropic itself has now identified the central limitation”.

“On 8 October, it said that while Glasswing partners had uncovered many vulnerabilities, the programme had ‘not yet achieved a sufficient reduction in cyber risk’ because verifying, prioritising and fixing those findings remained difficult.

“We are becoming much better at finding vulnerabilities, but finding a vulnerability is not the same as removing the risk. Organisations must still validate and prioritise findings, develop and test fixes and deploy them safely.”

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Updated, 2.30pm, 13 October 2026: This article has been updated with comments from Forrester senior analyst Madelein van der Hout.