Warnings issued as grocery store fridges in seven European countries hacked in suspected cyber attack

UK supermarkets are on the alert after fridges and freezers in supermarkets across Europe were hit by a cyber attack, leading to them warming up.

Supermarkets in seven European countries were affected by the attack, including shops operated by Delhaize in Belgium and Luxembourg where the majority of the affected shops were located, around 40 in total.

Outlets in Finland, Estonia, Ireland, the Netherlands, and Sweden were also affected during the outage.

This saw the evaporators in the freezers switch over to defrost mode, meaning that they slowly warmed up and caused the food inside to defrost and have to be thrown away.

Stephan Moelans is the CEO of Sabcobel who operates the systems used by food retailer Delhaize, and has confirmed that the company was targeted by a cyber attack.

Moelans said that the business has now been 'working all night and morning to disconnect the affected units from the network'.

"The simplest solution is to manage the fridges over a secure internet connection. Most of our customers switched to that after the attack in France," Moelans said.

A notice informing customers of the problem (Wiktor Dabkowski/Bloomberg via Getty Images)

The majority of fridges which are used in European supermarkets are connected to the internet. This was put in place to allow basic maintenance to be carried out remotely, but has also created a vulnerability in that hackers could also gain access to the units, leading to incidents such as this.

Freezers in shops saw their temperatures rise as high as 50C, around 122F, according to reports.

One branch of Delhaize in Flanders in northern Belgium has told local media outlet Het Laatste Nieuws that it lost around €100,000 worth of products, equivalent to just under $112,000.

The branch manager explained that this was also just the actual products which had been lost, and didn't account for the money lost by the store having to close while the problem was fixed.

It comes after a similar incident saw hundreds of French supermarkets also affected by their freezers turning to defrost mode, resulting in the loss of large amounts of food.

Media reported that millions of dollars' worth of food was lost in the attack in October after defrosting or not being kept at safe temperatures, meaning it had to be thrown away.

Countries hit by the outage (UNILAD)

Moelans has also said that the company has since worked to 'protect our customers fridges against this vulnerability', explaining that the units need a physical alteration to guard against it, not just updates to their software.

At present it is not clear who is responsible for the alleged cyberattack.

Several companies were affected, including french owned company Carrefour, who said that 15 of their stores in Belgium had been affected and that they had taken meaxures to keep stores open.

Another was Colruyt Group, which franchises Spar stores in Belgium, and said five of its stores were affected.

IKEA has also said that fridge systems in Mons, in Belgium, were affected, with a spokesperson saying that the company 'cannot rule out that additional locations may be affected'.

Meanwhile Swedish grocery retailer ICA was affected, saying in a statement that a 'small number of ICA stores operating outside ICA's central network' were hit and that it 'is currently supporting the affected stores in managing the situation'.