MalwarePublished 13 Jul 2026Updated 5 Aug 2026

permcserver (npm) · Malicious Code

Affects permcserverSource GCVE Database

Malicious package : remove permcserver and rotate any secrets on hosts that installed it.

Data as of 26 Oct 2026, 15:56 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-10489

What to do

Remove permcserver from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.

Affected software

Product	Affected	Fixed in
npmpermcserver	Affected 1.0.0 – 1.0.4 5 affected builds	Fixed in–

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Description

The permcserver npm package contains malicious code that, when imported, starts a native proxy server embedded in a bundled shared library. This proxy server authenticates clients using a hardcoded UUID and allows authenticated users to tunnel TCP traffic through the host machine, effectively turning it into a backdoor. The package disguises itself as a Minecraft/Pterodactyl server helper by serving decoy content, but its true function is to provide attacker-controlled network relay and arbitrary native code execution within the Node.js process.

Impact

Importing or requiring the permcserver package on a host machine results in the immediate activation of a backdoor proxy server that allows an attacker who knows the hardcoded UUID to tunnel arbitrary TCP traffic through the compromised host. This grants persistent, authenticated access and the ability to execute arbitrary native code within the Node.js process, potentially leading to full system compromise or lateral movement within a network.

Defensive guidance

Users should avoid installing or importing permcserver versions 1.0.0, 1.0.1, and 1.0.3. Remove any existing installations of this package immediately. Monitor for any unauthorized network proxy activity and consider scanning for the presence of this package or its native components. Since this is a malicious package, do not trust any decoy content it serves.

Summary

The permcserver npm package (versions 1.0.0, 1.0.1, and 1.0.3) includes a 10-line JavaScript shim that loads a native shared object (lib-linux.so) implementing a VLESS-over-WebSocket proxy server. This proxy uses a hardcoded UUID for client authentication and supports SOCKS5/HTTP upstream proxies, enabling an attacker with the UUID to establish persistent, authenticated TCP tunnels through the host. The package exports no API and immediately activates the proxy upon import. It also attempts to conceal its malicious behavior by enumerating environment variables related to hosting panels and serving decoy HTML content consistent with Minecraft server management, misleading users about its purpose. The native code symbols indicate relay and TCP dialing functionality, confirming its role as a backdoor.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Jul 2026, 09:52 UTC

Technical details

References

Community reviews