European grocery stores have experienced a new wave of suspected cyberattacks involving sudden temperature fluctuations in fridges and freezers.

Local reports shared by Bloomberg and Reuters indicate that major supermarket chains in Estonia, Luxembourg, Belgium, and Sweden were impacted. An Ica Kvantum store in Sweden announced on Facebook that hackers breached its cooling systems overnight, remotely increasing temperatures to 50 degrees Celsius (122 Fahrenheit).

Dutch retailer Ahold Delhaize attributed the temperature adjustments in dozens of its supermarkets across Belgium and Luxembourg to an “IT incident”. These events follow a previous cyberattack last month that targeted hundreds of French supermarket refrigerators, causing food spoilage estimated to cost millions of Euros. Approximately 40 Delhaize supermarkets and 15 Carrefour stores in Belgium were affected by the breach.

Several ICA and Coop shops in Sweden were hit, while thirteen SuperValu shops in Ireland also faced impacts. Local media reported that thousands of euros worth of food had to be discarded as a result.

Delhaize, one of Belgium's biggest supermarket chains, told Belgian media a "computer incident" had occurred overnight at 40 shops.

Carrefour, a French-owned supermarket, said it was "currently analysing" the incident at 15 of its Belgian stores.

"ICA is currently supporting the affected stores in managing the situation," the spokesperson said. The IVA branch in Sjöbo was closed earlier but has now reopened to customers.