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 has sent a warning email to users that installed removed game PirateFi on Steam, explaining that it included suspected 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.”

This sort of thing is atypical for Steam. The automated systems for game updates can sometimes crash PCs when the updates are problematic, but so far Valve has done a very good job of keeping actual malware out of the Steam store. (Can’t say the same for Apple, Google, or Microsoft .)

Valve is warning Steam users that an indie developer uploaded builds of its new survival sim game that contained malware.

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.