Threats Tagged 'obfuscation'

Since late March 2026, a large-scale phishing campaign has been deploying malware including Agent Tesla, Remcos, XWorm, and Best Private LOGGER through fileless techniques and low-detection Lua-based loaders. Attackers impersonate well-known companies using business cooperation lures to distribute malicious archives containing obfuscated JavaScript files. These scripts deploy either AutoIt or LuaJIT interpreters alongside disguised scripts masquerading as TrueType Font (.ttf) files. The Lua loaders employ sophisticated anti-analysis techniques including custom ROT ciphers, decoy memory allocation, and Donut shellcode generation for reflective in-memory payload execution. The campaign evolved from simpler implementations in October 2025 to highly complex versions by June 2026, incorporating API unhooking and advanced debugging countermeasures. Victims are ultimately infected with Remote Access Trojans and infostealers that enable full system control and extensive data exfiltration.