A global phishing campaign active since late March 2026 deploys heavily obfuscated JScript droppers that launch LuaJIT or AutoIt-based loaders disguised as TrueType Font (.ttf) files to deliver multiple RATs and infostealers including Agent Tesla, Remcos, XWorm, and a Snake Keylogger variant dubbed Best Private LOGGER. The Lua loader leverages LuaJIT's Foreign Function Interface to call native Windows APIs for in-memory shellcode execution, employing advanced evasion techniques such as decoy memory allocation, Donut header patching, AMSI/ETW bypass, API unhooking, and VEH-based segmented shellcode decryption. The campaign has evolved from October 2025 through June 2026 with progressively more sophisticated anti-analysis capabilities.
Donut Shellcode
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The TTF Trap: A Global Campaign of a Low-Detection Lua Loader