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Finnish Residents Briefly Left in Cold After DDoS Attack

A DDoS attack apparently striking another target had a knock-on effect on a Finnish residential heating system.

Recently, DDoS attacks have been used to censor journalists' websites, and even temporarily make high profile sites such as Twitter as Spotify partly inaccessible. But in Finland, a DDoS led to something else entirely: a disruption last week of the heating system for a couple of residential buildings, reported.

The episode highlights the knock-on effects that DDoS attacks can sometimes have. Just as the Twitter outage was because of a DDoS against DNS servers, this Finnish outage was due to an attack against another target, according to the Finnish Communications Regulatory Authority.


Simo Rounela, CEO of Valtia, a Finnish company that manages the buildings, told Motherboard that the attack hit a DNS service; that is, servers that translate human-readable internet domain names into computer IP addresses.

Shortly after, Valtia received a number of alerts from one of their building's automation systems, made by a company called Fidelix.

"Remote connection was not working, so went on-site for more inspections," Rounela explained. The automated system controlling the heating, ventilation and hot water for the homes kept rebooting every 5 minutes. Eventually, it just didn't boot-up anymore, he said.

Disconnecting the system from the internet fixed the problem, Rounela said, and they managed to get it up and running again about an hour after the original alarm.

Clearly, this wasn't a catastrophic interruption, but it still shows how the interconnected nature of the internet can have consequences for our physical world too.