Styx Stealer is a new malware targeting Windows computers, designed to hijack cryptocurrency transactions by replacing wallet addresses in the clipboard with those of attackers. It also steals sensitive data, including private keys, browser information, and Telegram sessions. The operator of Styx Stealer inadvertently leaked sensitive client data from their own machine, marking a significant operational security (OPSEC) failure. This leak exposed the client list and profit details of the malware's creator.