OpenSSF/OSV advisory MAL-2026-11168 confirms this npm version as malicious. Package is advertised as a small PostCSS plugin that injects CSS variables and adds -webkit- prefixes, but its `main` (index.js) is a 164 KB single-file Bun-bundled artifact wrapped in a bytecode-VM obfuscator: a rotated string array (`vmZ`) with a shift-based decoder, a VM interpreter (`vmT_21dbca`), and a payload table of ~20 large base64 blobs, several of which decode to opaque binary-shaped bytes...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in postcss-motion-utils (npm)
Details
Package is advertised as a small PostCSS plugin that injects CSS variables and adds -webkit- prefixes, but its `main` (index.js) is a 164 KB single-file Bun-bundled artifact wrapped in a bytecode-VM obfuscator: a rotated string array (`vmZ`) with a shift-based decoder, a VM interpreter (`vmT_21dbca`), and a payload table of ~20 large base64 blobs, several of which decode to opaque binary-shaped bytes. The file begins with the `// @bun` header and a `while(!![])` string-array rotation loop. Because this file is the module main, the VM and its embedded payloads execute on `require('postcss-motion-utils')`. The declared PostCSS functionality does not require bytecode-VM obfuscation or embedded binary blobs; the shape (opaque decoder + rotated string array + base64-encoded inner payloads executed at import) matches the structure of hidden supply-chain payloads rather than a CSS utility library.
## Source: ghsa-malware (35e5cd51d2131c9af1800f9ece6bda2d695d523a36394222e10bc88554e7c935) 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 postcss-motion-utils@3.2.7 as malicious (MAL-2026-11168): Malicious code in postcss-motion-utils (npm)