A notice informing customers that refrigerators are temporarily out of service is displayed on an empty refrigerated case at the Delhaize Shop & Go store. ( Reuters: Stephanie Lecocq )
Supermarket chains across Europe have reported an IT incident which led to changes in fridge and freezer temperatures.
Believed to be a cyberattack, the incident has affected four supermarket chains.
The head of Sweden's national cyber security centre said it had "become clear" how many operational technologies are exposed, and need to be protected.
Four supermarket and grocery chains across Europe reported an IT incident impacting fridges and freezers overnight, with one company attributing the temperature spikes to a cyberattack.
Dutch supermarket chain Ahold Delhaize, and Belgian chain Colruyt said on Monday an IT incident overnight hit cold storage in dozens of stores in Belgium and Luxembourg, while Swedish grocers ICA and Coop reported similar temperature spikes.
The incidents follow an attack in France last month, in which police said hackers seized control of cooling units at hundreds of supermarkets, raising temperatures up to 50 degrees Celsius, causing fires and food losses.
Fridge aisles in France remained closed after hackers raised temperatures causing widespread food spoilage. ( Reuters: Stephane Mahe )
Ahold Delhaize also reported a cybersecurity incident to Dutch police last month after it detected suspicious activity in its infrastructure.
On Monday, Ahold Delhaize realised there had also been temperature increases in the cooling systems, according to company spokesperson Sarah De Meester.
The company is investigating the incident.
Stephan Moelans, the CEO of Belgian refrigeration company Sabcobel, which operates Ahold Delhaize's systems, told Belga news agency the incident was a cyber attack, in which the units' evaporators were switched to defrost mode.
Empty refrigerated shelves are seen inside a Delhaize Shop & Go store after an overnight IT incident. ( Reuters: Stephanie Lecocq )
Mr Moelans' office declined to comment when contacted by Reuters.
A spokesperson for Colruyt Group, which operates Spar stores in Belgium under a franchise system, said the fridge system were attacked in five shops.
From refrigerators and heating systems to security cameras and alarm networks, an expanding range of devices once largely mechanical can now be monitored and controlled remotely, creating new opportunities for cybercriminals.
Authorities have not indicated who could have been behind last month's incidents, and there were no claims of responsibility.
The head of Sweden's national cybersecurity centre, John Billow, told Reuters it was working on several incidents regarding refrigeration systems in grocery stores around Sweden.
One Swedish ICA store said on social media the temperature of its refrigerators and freezers had been "hacked" overnight and set to 50 degrees.
At an ICA Baronen store in Stockholm, a notice said all the shop's freezers were broken due to a cyber attack. The store's sales manager said the attack happened at 2AM local time, and was noticed at 5.30AM.
A chain grocer in Sweden has also experienced issues with cyber security, and the fridge systems it uses. ( ABC Pilbara: Lina Elsaadi )
"We are aware that a limited number of stores were affected by an incident overnight, which impacted their refrigeration and freezer systems," a spokesperson for ICA said.
Grocery retail group Coop told Swedish news outlets six of its stores had been affected by similar incidents. It did not immediately respond to a request for comment.
"We have in recent weeks… identified that we have quite a lot of exposed operational technology devices in Sweden that we have been clear about the necessity to update or patch," Mr Billow said.
An overnight IT incident affected cooling and freezer systems in a number of stores in Belgium and Luxembourg, causing temperature spikes in refrigeration units. ( Reuters: tephanie Lecocq )
An Estonian supermarket chain was also affected, with temperatures set to 50 degrees, technology supplier Kitman Coldtech told public broadcaster ERR.
"This is very fresh, it happened this morning," Kitman CEO Jann Mutso told ERR.
He declined to name the affected grocery chain.
