Sure, that's possible?

It's also possible that, because the US is busy bombing Iran, Iran may be busy attacking the US infrastructure in any way possible? The US is also in a tepid war with russia, last I checked.

Some "cyber" crew getting a shell on an outsourced service provider and running a "defrost" command is also a totally explanation for this situation. It's also totally possible that some crew has mapped out a list of PLC entry points for various orgs and has them in a spreadsheet of "if we find a vulnerability, we should X this Y with this prestaged script that our intern / LMM cooked up last year to defrost these freezers"