Valve recommends that users who downloaded PirateFe run a full system scan with anti-virus software and check for auspicious or newly installed software on their PPCs. As a last resort, Valve also recommends that users consider reinstalling Windows to completely rid their system of any potential malware.

Valve removed a game from its Steam video game platform and store because it contained malware, according to media reports. In its notice to users who downloaded the game, Valve said affected users may want to “consider fully reformatting your operating system.”

The free-to-play game, PirateFi, infects users with malware that steals browser cookies, enabling the malware’s creator to hijack access to various online accounts.