In recent months, a new infostealer malware known as REMUS has emerged across the cybercrime landscape, drawing attention from security researchers and malware analysts. Several technical analyses published in recent months focused on the malware’s capabilities, infrastructure, and similarities to Lumma Stealer, including browser targeting mechanisms, and credential theft functionality and more. However, far less attention has been given to the underground operation behind the malware itself. An analysis conducted by Flare researchers of 128 posts linked to the REMUS underground operation between February 12 and May 8, 2026, provides a rare look into how the group presents, develops, and operationalizes the malware within underground communities. By analyzing the actor’s advertisements,…