Silver Fox Springs Tax-Themed Attacks on Orgs in India, Russia

A China‑backed APT tracked as "Silver Fox" ran a large tax‑themed social‑engineering campaign (over 1,600 messages) targeting organizations across India and Russia. The campaign delivered multiple tools including a previously undocumented backdoor dubbed ABCDoor, the ValleyRAT remote access trojan, and other malware to establish persistent access, credential theft, and data exfiltration. The attacks used tailored lures and widespread phishing to hit multiple sectors, indicating an espionage‑oriented, scalable operation.