Latest Xloader Obfuscation Code & C2 Protocol

This technical analysis of Xloader (FormBook rebrand) details enhancements since version 8.1: more sophisticated code obfuscation (encrypted strings, runtime-decrypted functions, opaque predicates), changes to function/egg construction, and an obfuscated custom decryption routine; it also documents Xloader’s network protocol and multi-layer RC4/Base64 encryption, its use of 65 decrypted C2 IPs (randomly probed to hide real servers), HTTP GET/POST behaviors for PKT2 and exfiltration, and the malware’s command set (file execution, update, self-removal, credential theft, payload download/execute, reboot/shutdown).