Skip to content

ENDLESSDOORS

Backdoor implant in ZBT/Zbtlink router firmware (CVE-2026-66747) that starts at boot, runs as root, and beacons outbound to a hardcoded C2 over cleartext TCP.

Current stories

securityConfirmed2 publishers

FBI disrupts the Nanjing contractor that sold QScan and QTRouter to Chinese espionage operators

QTYF built and ran the scanning and routing frameworks other Chinese teams pointed at U.S. critical infrastructure. That means the proxy addresses and scan fingerprints in your logs point to the supplier; the intruder behind them stays unnamed.

Perspective Coverage

3 publishers
Builder
Builder 23%
Operator
Operator 58%
Investor
Investor 19%

Reality

Evidence55
Adoption
Not scored
Hype gap+10
Incentives
Not scored
Confidence60
buildOne report1 publisher

A root implant in ZBT router firmware takes orders from whoever holds the C2 position

VulnCheck says SPEAKINGSTONE beacons as root over cleartext UDP with no authentication. Control passes to anyone who occupies that channel, and a second implant in the same firmware image turned up in 22 countries.

Publishers:docs.vulncheck.com

Reality

Evidence58
Adoption40
Hype gap+12
Incentives76
Confidence55
buildOne report1 publisher

Answering one hardcoded address gives you root on 20+ Zbtlink router models

VulnCheck's ENDLESSDOORS ships enabled on more than 20 Zbtlink models and runs as root from boot, and because it opens no port at all, the check that would have caught it has to happen on the firmware image.

Publishers:docs.vulncheck.com

Reality

Evidence58
Adoption32
Hype gap+18
Incentives74
Confidence52
productOne report1 publisher

Two Nim implants shipped inside a US-branded router VulnCheck bought on Amazon

VulnCheck rooted a Deep Orange LTE router sold by a US supplier and found a WAN-facing backdoor listening on UDP 9992, plus a hard-coded checksum key that names the Chinese OEM behind the firmware.

Publishers:vulncheck.com

Reality

Evidence72
Adoption55
Hype gap+10
Incentives68
Confidence60
securityOne report1 publisher

ZBT router firmware ships two factory implants that beacon out on UDP/10000

SPEAKINGSTONE and DARKLANTERN both hand unauthenticated attackers root on ZBT-built hardware, and because neither advisory names a fixed firmware release, the remedy for an affected model is replacing it.

Reality

Evidence64
Adoption38
Hype gap+12
Incentives72
Confidence62