Valve has awarded $20.000 US to hacker Artem Moskowsky for disclosing a game key hack. The hack gave Moskowsky access to previously generated CD keys for any game on the platform.
The security hole that Moskowsky discovered and exploited for a proof of concept was part of Steam's developer tools. It provided unlimited access to all previously generated CD keys for games on the platform, including those not activated yet.
If knowledge about the security hole fell into the wrong hands, the exploit could have had more severe consequences. That being said, Valve's continuous logging of the Steam platform would have likely triggered internal alarms.
The hack was reported to Valve on August 7, 2018, and was publicly disclosed on October 31, 2018.