A hacking attack that targeted supermarkets across Europe on Monday raised temperatures in refrigerators and freezers at dozens of stores. 

Dozens of supermarkets in Belgium, Luxembourg and Sweden were hit by the attack, and many were forced to throw away food that had spoiled, Reuters reported. 

A sales manager at a store in Stockholm told Reuters that the attack occurred around 2 a.m., raising the freezers' temperatures, which wasn't noticed until hours later. 

The attack is similar to one that targeted supermarkets in France last month, causing fires and food losses.