Tech Optimizer
April 22, 2026
A newly identified remote access trojan, STX RAT, emerged in 2026, integrating hidden remote desktop access with credential theft features. The name "STX" comes from the Start of Text magic byte x02, which it appends to communications with its command-and-control (C2) server. Initial sightings were reported in late February 2026, when it was delivered via a browser-downloaded VBScript file to a financial organization. By early March, Malwarebytes noted a campaign distributing STX RAT through compromised FileZilla installers. Researchers from eSentire’s Threat Response Unit analyzed the malware, which includes extensive anti-analysis measures and employs techniques like AMSI-ghosting. Once operational, STX RAT connects to a C2 server at 95.216.51.236, transmitting system information securely. It targets saved credentials from applications like FileZilla and includes a Hidden Virtual Network Computing (HVNC) module, allowing attackers to control a victim's machine without detection. Security teams are advised to block the C2 IP and implement detection rules to mitigate the threat.
