France on Monday formally blamed Iran's Islamic Revolutionary Guard Corps (IRGC) for a cyberattack last month that sabotaged refrigeration systems at around 700 supermarkets across the country, spoiling tonnes of food and in some cases starting fires.

Foreign Minister Jean-Noël Barrot called the attack "unprecedented in both its scale and its level of aggression" and "the first large-scale cyberattack carried out for sabotage purposes on French national territory." He was speaking on the sidelines of a meeting of G7 foreign ministers in Paris, where he also announced that Iran's ambassador had been summoned to the foreign ministry.

How the attack worked

On the night of October 11–12, hackers broke into the internet-connected refrigeration systems of supermarkets and food retailers across France and remotely overrode their temperature controls, switching on defrost cycles that drove temperatures up — in some cases to 50°C. Fresh and frozen produce spoiled, millions of euros' worth of stock had to be thrown away, and fires broke out in at least 15 cases as overheated equipment caught alight.

More than 100 Coopérative U stores and 180 Intermarché and Netto outlets were hit, according to reports, with Intermarché saying at least 300 of its stores were affected. The refrigeration systems were managed remotely through software supplied by the Danish engineering firm Danfoss. France's cybersecurity agency, ANSSI, said the intrusions were made possible by what its director general, Vincent Strubel, described to senators as "elementary security flaws" — including weak passwords on internet-exposed equipment.

The attribution

ANSSI and the government's computer emergency team, CERT-FR, attribute the attack to Shahid Kaveh, an offensive cyber unit they place inside the IRGC's Electronic and Cyber Centre. The Paris public prosecutor, Laure Beccuau, has opened a formal investigation and is seeking international arrest warrants for the unit's leader and his two deputies. French officials say the attribution rests on the infrastructure used, the tools deployed, traces of Persian in the attack code, and the unit's known methods.

France has not published the intelligence behind the attribution, and Iran has issued no formal response. Iran's mission to the United Nations did not respond to requests for comment, and Tehran generally denies carrying out malicious cyber operations.

What happens next

Mr. Barrot said France would pursue further sanctions against Iran at European Union level, and on Tuesday added that Paris ruled out "nothing" in its response, saying it would take "all measures — including those we may not disclose publicly — that we deem proportionate and necessary to deter any further attacks."

The episode is the first formal attribution of its kind — a state publicly blamed for a destructive cyberattack on civilian food infrastructure. Similar suspected freezer attacks were reported in other European countries on November 2, but no official source has linked that wave to Iran. For now, the French case stands alone: a supermarket fridge, hacked from abroad, turned into a weapon against a country's food supply.