'Unprecedented' Cyberattack cripples supermarket fridges across Europe as hackers activate automatic defrosting — delivery and store prices also impacted by incident

What’s missing from this report is more detail on how exactly this attack went down. Did the attackers compromise supermarket networks and manipulate the fridges through lateral movement within the network; or were the fridges accessible from the open internet? If the latter is the case (and there’s a non-zero likelihood they were): why the fuck?