Silver Fox uses fake tax notices to spread ValleyRAT and new ABCDoor backdoor

Silver Fox is using fake tax authority notices to infect organizations with ValleyRAT and a newly documented Python-based backdoor called ABCDoor. The campaign first appeared in December 2025 with phishing emails impersonating India’s tax service. A similar wave followed in January 2026 against Russian organizations. The emails were designed to look like official tax audit […] The post Silver Fox uses fake tax notices to spread ValleyRAT and new ABCDoor backdoor appeared first on VPN Central.