Researchers Find Persistent Backdoor in Zbtlink Routers

2026-08-07

VulnCheck researchers discovered an intentional and unpatchable backdoor dubbed EndlessDoors in over 100,000 active Zbtlink and Wiflyer routers that initiates outbound command-and-control connections to bypass NAT, requiring defenders to monitor port 7000 for malicious beacons and physically replace the compromised hardware.