Cyberattacks crank French supermarket refrigeration systems up to 50°C

Cyberattacks on supermarket refrigeration systems reportedly pushed temperatures as high as 50°C (122°F), affecting hundreds of stores in France and forcing retailers to discard food.

Major supermarkets such as Carrefour, Coopérative U, Intermarché, Monoprix, and more were hit by the attacks, which spoiled perishable food and left stores without fresh produce.

The affected equipment includes cold-storage units used to hold food before it reaches supermarket shelves.

The criminals behind the attack raised temperatures to unsafe levels, spoiling food and in some cases starting fires.

Some affected retailers used refrigeration controllers produced by Danish company Danfoss.

Authorities have not identified the entry point or confirmed exploitation of the vulnerabilities previously disclosed by Claroty and patched in August 2025, although the manufacturer said affected stores were running outdated firmware.

Experts say the previously identified vulnerabilities were easily scriptable and relied on a unique but predictable authentication method.

Claroty found a hidden authentication mechanism in the AK-SM 800A platform that accepted a code generated from the device's current date, bypassing the configured administrator password.

Anyone who reproduced the algorithm could generate a valid daily code and gain administrative access.

"It's a zero-skill thing to pull off, I wrote the bash script while having a shit," said security pro Kevin Beaumont.

The research demonstrated how compromised controllers could expose refrigeration systems to physical disruption, although the vulnerabilities' role in this week's attacks remains unconfirmed.

Danfoss told reporters this week that the French supermarkets affected by the attacks "were running outdated firmware" and that the company has consistently advocated for keeping systems updated.

The Register asked Danfoss if it would confirm whether the previously disclosed bugs were exploited to execute the attacks, and whether the same bug was also abused in August to compromise US military commissary refrigerators, which led to food losses.

CERT-FR published an alert reporting numerous compromises of Danfoss AK-SM and AK-SC controllers, which were not mentioned in Claroty's original reporting nor in Danfoss's advisories at the time.