MAL-2026-12371

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/eth-codegen/MAL-2026-12371.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12371
Published
2026-08-05T12:58:43Z
Modified
2026-08-05T13:35:22.236979863Z
Summary
Malicious code in eth-codegen (npm)
Details

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

Source: amazon-inspector (c111948c855e4133fbd037c268523a2118038ca498e9bdba1c743d4ee77f24bc)

The package advertises itself as an Ethereum codegen utility but its actual contents are an unrelated mongoose leanhooks plugin plus a hidden dropper. index.js appends an async runHandler() concealed after ~1KB of whitespace padding following the module.exports = leanhooksPlugin; line. On require, runHandler() performs axios.get('https://www.jsonkeeper.com/b/VYFER'), then passes the response's cookie field to new Function('require',...) and invokes it with the installer's require. jsonkeeper.com is an anonymous, mutable paste host controlled by whoever created the paste, giving that party arbitrary code execution in the installer's Node process every time the package is imported. The whitespace concealment plus cover-story package name/description are deliberate evasion.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "c111948c855e4133fbd037c268523a2118038ca498e9bdba1c743d4ee77f24bc",
            "id": "IN-MAL-2026-014832",
            "modified_time": "2026-08-05T12:58:43Z",
            "import_time": "2026-08-05T13:08:49.873312681Z",
            "source": "amazon-inspector",
            "versions": [
                "0.5.4"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / eth-codegen

Package

Name
eth-codegen
View open source insights on deps.dev
Purl
pkg:npm/eth-codegen

Affected ranges

Affected versions

0.*
0.5.4

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "d64e6702f4d128a917c69697382aa5ff32c2243edb869c8fda082c10edfb4a01",
            "path": "index.js",
            "tlsh": "2661aa7865bad601a53332f18cfa1246da75c037054a90d9fcaec2d4ab30814196fff8"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-rOdfnxGrFWzJ/2LIIfC8NkgIn5r1LVg3yefosSZuq0F5Q14w+3mRU/GHLBr9b4iCQ46asaA66WF3FKUHxIv5iQ==",
                "sha1": "af5f30de95519238844281eaf394901177d50572"
            },
            "filename": "eth-codegen-0.5.4.tgz"
        }
    ]
}
cwes 
[
    {
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/eth-codegen/MAL-2026-12371.json"