Researchers discovered a cross-site scripting (XSS) vulnerability in the web-based control panel of the StealC info-stealing malware. This flaw allowed them to monitor the malware operators' active sessions and collect data on their hardware setups. StealC is designed to steal sensitive information from users, which means this incident not only exposes the attackers but also raises concerns about the ongoing effectiveness of such malware. Understanding these vulnerabilities can help cybersecurity experts develop better defenses against similar threats. The incident serves as a reminder that even sophisticated malware can have weaknesses that researchers can exploit to gain insights into cybercriminal operations.