Of note is that even if the Steam wasn’t breached, but instead a 3rd party service, those numbers are still compormised.

While the company didn’t link the attack to a specific threat group, BleepingComputer has learned that the Akira ransomware operation is behind the breach. A source familiar with the matter also said the ransomware gang stole files from Hitachi Vantara’s network and dropped ransom notes on compromised systems.