Hackers have forced the temperature of many French supermarket fridges up to 50C overnight, in an “unprecedented” cyber-attack affecting several hundred stores across the country, with fires and food losses reported.
The Paris prosecutor’s office said on Monday the large-scale attack was “affecting connected refrigerators in several major food retailers across France”. Reported damage included “food losses and fires”, it added.
The prime minister, Sébastien Lecornu, instructed France’s national cybersecurity agency ANSSI to investigate, a person in his office said.
France “was coordinating with its European counterparts, as other countries may also be affected”, while also investigating whether any other French firms were at risk, they said.
They often have pretty powerful heaters for defrosting, even your household fridge has a heating coil tucked inside somewhere: Ice takes a lot of energy to melt quickly, and refrigerators are very well insulated so once they’re heating up there’s nowhere else for the heat to go. Refrigeration (using phase change) is paradoxically much more energy efficient than electric resistance heat (which is what is usually used for defrosters, because of cost minimization) so it’s not uncommon for the defrost heater to be significantly more powerful than the whole refrigeration side, because the defrost heater is only intended for very occasional use to literally de-frost the coils before turning off again. In this case, it sounds like the de-frost heater was used repeatedly or indefinitely and the cooling shut off.