I'm extrapolating a bit here based on Reddit hearsay, but I think this may have to do with rural stores having essentially consumer-grade internet routers connected to the mobile broadband network.
Much of the coverage in Swedish media drives the point that only 4G-uplinked stores have been hit so far. I think that's unfortunate, because really it wouldn't have differed if these stores were connected by 5G.
I'm guessing here, but my money would be on freezer ICS systems being made available to the world by accident by way of NAT-PMP on a consumer router. In Scandinavia you can bypass CG-NAT on mobile connections by setting a particular APN, so my guess is that these control systems were simply findable on Shodan.
This also explains why this wasn't discovered after the recent French breach. Supposedly all the stores with "proper" uplinks were in compliance, and no one had thought of a way in for those non-compliant stores, because they "weren't even connected, so how would an attacker get in?"
Many of these smaller stores (and probably some of the larger ones too) rent or lease refrigeration equipment from one of a handful big providers. These are large and expensive systems, and there is costly paperwork involved together with logistics suppliers to show that the cold chain is satisfactory.
These refrigeration providers work with local contractors and HVAC companies to set things up. Their installation techs do what they think is required to remotely operate these systems. If you bring up the question keeping these systems offline or at least on airgapped networks you will most likely get a shrug as reply.
This is not a technology problem. This is problem of responsibility. One can hope things will improve when litigation starts happening, but it doesn't look good considering these people had literally months of notice since the well-publicized attacks on the American fridges, then the French fridges, and now these.
All of the fridges stayed online after the hack. I ran a Shodan scan a few days later, and the number of reachable fridges actually increased. The first hack might have been a surprise, but anyone who was IT in a refrigerator management company should have been able to run a (free) Shodan scan like mine and get the whole list.
> I'm guessing here, but my money would be on freezer ICS systems being made available to the world by accident by way of NAT-PMP on a consumer router.
Why would there be accidental port mappings on their router though? I could maybe see owners setting it up so they could monitor from home, but even that is a bit of a stretch for rural supermarket owners
absolutely unbelievable (even by the very low standards I see, being in iot myself) that any commercial equipment would be doing upnp
someone manually poking a hole in their firewall is way more likely
"... I think this may have to do with rural stores having essentially consumer-grade internet routers connected to ..."
It has to do with refrigerators reachable on the Internet.
If the refrigerators were not reachable on the Internet, none of this fragility would exist.
The fragility of refrigerators reachable on the Internet was demonstrated just a few weeks ago. These refrigerators were left connected to the Internet.
This lack of discernment and misunderstanding of risks and fragility will not be solved with a better router or a different uplink.