npm · Malicious package advisory
Malwarecss-logical-prop-shim
GHSA-7g6f-95c5-ghgv
Malicious code in css-logical-prop-shim (npm)
Details
**Severity:** Critical
**Affected versions:** `= 1.0.0`
## Source: amazon-inspector (d0ffba65f80ee8f200199c8c90ebb6297b8590537c80ea50bb34874d91665b5f)
The package ships thunderboltRegistry.js which imports child_process and invokes execSync with curl commands at multiple sites (lines 30, 39, 47, 48). The declared purpose of the package is a CSS logical-property shim, which has no legitimate need to spawn shells or make outbound curl requests. The co-location of child_process + repeated execSync('curl...') calls in a package whose stated purpose is a frontend CSS polyfill is the shape of a dropper or exfiltration helper rather than library code, and the file name 'thunderboltRegistry' is unrelated to any CSS functionality.
---
Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/7a1f1382a84618fabc1c45e8b61e9c9cea6ea33f/osv/malicious/npm/css-logical-prop-shim/MAL-2026-17482.json))
**References:**
- https://github.com/ossf/malicious-packages/blob/7a1f1382a84618fabc1c45e8b61e9c9cea6ea33f/osv/malicious/npm/css-logical-prop-shim/MAL-2026-17482.json
- https://www.npmjs.com/package/css-logical-prop-shim/v/1.0.0
- https://github.com/advisories/GHSA-7g6f-95c5-ghgvCompromised versions (1)
- = 1.0.0
Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.