China-linked PlugX and Bookworm Target Asian Telecoms
🔍 Cisco Talos and Palo Alto Networks Unit 42 describe concurrent campaigns distributing a revised PlugX variant and the long‑running Bookworm RAT against telecommunications and manufacturing organizations across Central and South Asia and ASEAN countries. Talos found that the PlugX sample borrows RainyDay and Turian techniques — DLL side‑loading of a Mobile Popup Application, XOR‑RC4‑RtlDecompressBuffer payload processing and reuse of RC4 keys — and includes an embedded keylogger. Researchers note the PlugX configuration now mirrors RainyDay’s structure, suggesting links to Lotus Panda/Naikon or shared tooling, while Unit 42 highlights Bookworm’s modular leader/DLL architecture, UUID-encoded shellcode variants, and use of legitimate-looking C2 domains to blend with normal traffic.
