MAL-2026-6336 Malicious code in sync-external (npm)
- Package
- sync-external
- Registry
- npm
What is MAL-2026-6336?
MAL-2026-6336 is a malicious package in sync-external, published on 23 Jun 2026.
Official description
The package ships an obfuscated JavaScript file at shim/index.js using hex-style identifier mangling (_0x391f3f, _0x3eff0a, _0x534564, etc.) characteristic of javascript-obfuscator output. Obfuscation alone is not proof of malicious intent — some publishers obfuscate for anti-tampering or anti-piracy reasons — but it prevents reliable assessment of the file's runtime behavior, and contextual tracing of the obfuscated code path was not available. No concrete evidence of credential exfiltration, install-time fetch-and-execute, silent-relay of caller data, or hardcoded attacker C2 was observed, but the inability to verify what the obfuscated shim does at load/use time leaves the residual risk unresolved. Recommend human review of the de-obfuscated content before trusting this package in a build pipeline.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
What should I do about MAL-2026-6336?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-vrc4-g2p2-9895.