Silver Fox Targeting India Using Tax Themed Phishing Lures

Description

A sophisticated campaign by the Chinese APT group Silver Fox is targeting Indian entities with authentic-looking Income Tax phishing lures. The attack leverages a complex kill chain involving DLL hijacking and the modular Valley RAT to ensure persistence. The campaign uses a multi-stage infection process, starting with a malicious email containing a PDF decoy. The payload is delivered through an NSIS installer, which drops a legitimate Thunder.exe binary and a malicious libexpat.dll for DLL hijacking. The final stage involves the Valley RAT, which uses a two-stage configuration loading mechanism and implements a 3-tier C2 communication loop. The RAT's modular plugin architecture allows for dynamic capability extension and persistence through registry-based storage.