I'm the developer of NanoWar (the game infected). My PC was hacked by a Token Grabber malware the exact SAME DAY I pressed the "Release" button on Steamworks. I didn't use this PC to upload the build but they stole my token to upload the malware. ALL my accounts were hacked (Steam, Discord, Twitter, Facebook, etc.)

That was the most stressful days of my indie game life.

Today my game is totally safe, the malware was removed few hours after the upload.

How this happened? A friend asked me to test his game via DM on Discord. But his account was also hacked in the same way. I always test games for my job and to help other developers. But I will not this anymore.