OpenSSF/OSV advisory MAL-2026-4531 confirms this npm version as malicious. On `npm install`, dist/postinstall.js base64-decodes the URL https://api.npoint.io/984b75c022a70cf00c39, fetches JSON from this anonymous mutable JSON-hosting service via axios, and pipes the response's `data.content` into a detached `node` child process's stdin for execution...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in clsx-js (npm)
Details
On `npm install`, dist/postinstall.js base64-decodes the URL https://api.npoint.io/984b75c022a70cf00c39, fetches JSON from this anonymous mutable JSON-hosting service via axios, and pipes the response's `data.content` into a detached `node` child process's stdin for execution. The fetch has no version pin, no hash/signature verification, and the source is operator-mutable — the attacker can swap the executed payload at any time. The package additionally typosquats the widely-used `clsx` utility (by Luke Edwards): name is a one-token edit, and the description, author name, email, and homepage are copied verbatim from the legitimate `clsx` to impersonate the upstream maintainer. The genuine `clsx` ships no postinstall; this fork adds one whose only purpose is the remote-code dropper. A malformed `Dependencies` (capital-D) field also lists `child_process`, a known squat name. Installing this package on any machine results in arbitrary attacker-controlled code execution under the installer's user account.
Decision reason
OpenSSF Malicious Packages via OSV confirms clsx-js@1.0.3 as malicious (MAL-2026-4531): Malicious code in clsx-js (npm)