Steam game mod delivered malware on Christmas Day – Epsilon Information Stealer was hidden in a Slay the Spire expansion

Over Christmas, a malware named ‘Epsilon Information Stealer’ infiltrated Downfall, a free mod on Steam, for the indie game Slay the Spire. The malware was present for an hour and solely in a standalone modified Downfall version, not the mod installed via Steam Workshop. The attack usually steals user passwords, but Downfall’s developer said accounts were compromised under different email addresses and none of these were stolen.