MalwarePublished 25 Jun 2026

ts-opus (npm) · Malicious Code

Affects ts-opusSource GCVE Database

Malicious package : remove ts-opus and rotate any secrets on hosts that installed it.

Data as of 26 Jun 2026, 22:35 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-6468

What to do

Remove ts-opus 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
npmts-opus	Affected =0.0.8	Fixed in–

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Description

The ts-opus npm package version 0.0.8 contains malicious code that injects a require call to an undeclared external module 'node-slot' inside files mimicking the legitimate big.js library. This causes execution of potentially arbitrary code from an external source at require-time, with all errors silently suppressed. This is a supply-chain attack targeting consumers expecting the genuine big.js package. Any system with this package installed should be considered fully compromised, and secrets should be rotated immediately.

Impact

Any computer with ts-opus version 0.0.8 installed or running is considered fully compromised. The malicious code executes arbitrary external code silently, potentially allowing an attacker full control over the system. All secrets and keys stored on the compromised computer should be considered exposed and must be rotated immediately from a secure, unaffected device. Removing the package alone does not guarantee removal of all malicious artifacts or backdoors introduced by this compromise.

Defensive guidance

Users should immediately remove this package from their systems. Because the package executes undeclared external code and silently suppresses errors, any system with this package installed should be treated as fully compromised. All secrets and credentials on the affected system must be rotated from a different, secure computer. Monitor for any unusual activity and consider rebuilding affected systems from known good backups.

Summary

The ts-opus package version 0.0.8 ships an unmodified copy of the legitimate big.js library but injects additional top-level code inside big.js and big.mjs that requires an undeclared module named 'node-slot'. This module is not listed in package.json dependencies, allowing the package to load an external module resolved at install time, which is outside the control of the ts-opus tarball. The injected code calls doc.from_str() on the required module, and all synchronous errors and promise rejections are caught and ignored, hiding any failure from the user. This behavior constitutes a targeted supply-chain attack, misleading consumers who believe they are using the authentic big.js library. The malicious code executes at require-time, potentially compromising the host system.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Jun 2026, 22:35 UTC

Technical details

References

Community reviews