Supermarkets across Europe face fresh cybersecurity scare after freezer temperature spikes

Supermarkets across Sweden, Belgium and Luxembourg report overnight temperature spikes in refrigeration systems, raising fears of a wider cyberattack following similar incidents in France and the Netherlands.

Supermarket chains in Sweden, Belgium and Luxembourg have reported sudden increases in the temperatures of their refrigerators and freezers across dozens of stores overnight. In the aftermath of similar incidents being linked to a cyberattack in France, the sudden temperature increases have prompted fears that the systems may have been manipulated remotely.

Sweden's food retailer ICA told the daily Aftonbladet on Monday that six of its stores had been affected. ICA later clarified that it was "aware of a limited number of stores" affected by the overnight incident, which impacted their refrigeration and freezer systems.

Before this incident, Dutch retailer Ahold Delhaize had reported a similar cybersecurity incident to the police in the Netherlands. The problem appears to have spread across Europe, as Belgian newspaper Le Soir reported that dozens of stores and supermarkets had been affected. These included five Spar outlets, multiple shops and Go convenience stores attached to Q8 service stations, as well as several Delhaize mini-markets.

The cyberattack in France

Back in October, hackers seized control of cooling units at up to 700 supermarkets in a large-scale attack that led to heavy losses of chilled and frozen food, underlining the vulnerability of internet-connected systems used for remote control.

During the attack in France, hackers overrode the settings on thousands of freezers, fridges and chiller cabinets, pushing temperatures from as low as -27°C to well over 50°C.

In the aftermath of the attack, stores had to discard vast quantities of fresh meat, dairy and frozen products, with many suffering significant losses.

The fact that supermarket cold-storage systems were connected to the internet to allow remote maintenance and alerts for system failures became a vulnerability that hackers exploited. They used external controllers supplied by Danish company Danfoss.

The attackers disabled alarm systems before adjusting the thermostats or extending the defrost programme by several hours. Danfoss said it had identified security flaws the previous year and had recommended updates that would have made such manipulation impossible.

A formal investigation was launched into the French attack.