MAL-2026-6342 Malicious code in therdweb (npm)
- Package
- therdweb
- Registry
- npm
What is MAL-2026-6342?
MAL-2026-6342 is a malicious package in therdweb, published on 23 Jun 2026.
Official description
The package's name 'therdweb' is a one-character variation of the popular 'thirdweb' SDK, while its contents (README, source code, author field 'Michael Mclaughlin', repository URL pointing at MikeMcl/big.js, version banner '7.0.1') are copied verbatim from the unrelated big.js library — the publisher is not the original author of either project. Both shipped entrypoints, big.js and big.mjs, contain an injected try/catch block that performs require("parket-slot") and immediately invokes doc.from_str() on it at module load, with the catch block left empty to swallow errors. parket-slot is not listed in package.json dependencies and is not mentioned in the README (which falsely claims 'No dependencies'); package.json additionally declares an undocumented dependency log-taker@^0.0.9. Any consumer that imports or requires this package will execute code from these external, undeclared/hidden modules controlled by the same actor, while the README hides their existence. This is the loader half of a multi-package install-graph dropper paired with name-confusion against thirdweb and identity impersonation of big.js.
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-2026-6342?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-g2vx-7x66-f2wv.