[lulagain]

A free-to-play game named PirateFi in the Steam store has been distributing the Vidar infostealing malware to unsuspecting users.

The title was present in the Steam catalog for almost a week, between February 6th and February 12th, and was downloaded by up to 1,500 users. The distribution service is sending notices to potentially impacted users, advising them to reinstall Windows out of an abundance of caution.

Malware on Steam

PirateFi was released on Steam last week by Seaworth Interactive, and received positive reviews. It is described as a survival game set in a low-poly world involving base building, weapon crafting and food gathering.

Earlier this week though, Steam discovered that the game contained malware but the service did not specify the exact type.

"The Steam account of the developer for this game uploaded builds to Steam that contained suspected malware," reads the notification.

"You played PirateFi (3476470) on Steam while these builds were active, so it is likely that these malicious files launched on your computer," the service warns.

The recommended measures for the notification recipients include running a full system scan using an up-to-date antivirus, checking for newly installed software they don't recognize, and considering an OS format.

Malware infiltrating the Steam store is not common, but it's not unprecedented either. In February 2023, Steam users were targeted by malicious Dota 2 game modes that leveraged a Chrome n-day exploit to perform remote code execution on the players' computers.

In December 2023, a mod for the then-popular Slay the Spire indie strategy game was compromised by hackers who injected an 'Epsilon' infostealer dropper into it.

Steam has introduced additional measures like SMS-based verification to protect players from unauthorized malicious updates, but the case of PirateFi shows that these measures are insufficient.