The Ubisoft flaw isn't the only unorthodox video game exploit around. Late last year, ReVuln—the same company that discovered the smart-TV exploit—found that the steam:// protocol of Valve's Steam application can be exploited to launch malicious code.
The problem actually lies in browsers that automatically execute steam:// commands without a confirmation warning (Safari) or with minimal information (Firefox). Once malicious code gains permission to run, it can then use Steam's legit capabilities or known vulnerabilities to fill your hard drive with all sorts of nasty stuff. Moral of the story? Don't set your browser to automatically allow Steam protocol executions.