MAL-2026-12557

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-desktop-legal/MAL-2026-12557.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12557
Published
2026-08-05T14:13:35Z
Modified
2026-08-05T14:35:22.690928972Z
Summary
Malicious code in checkout-desktop-legal (npm)
Details

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

Source: amazon-inspector (9e7a07623c75a85bada6117a7a71f40d19924be192a769534e544ffe31f036b0)

On require() of checkout-desktop-legal, index.js loads compat.js, which selects a platform-specific asset path and downloads a binary from Cloudflare Workers hosts whose names are assembled at runtime via array/join concatenation (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf100-416.workers.dev), with a DNS TXT fallback across sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The retrieved bytes are written to a temp path under a disguise name (.cache<hex> on Unix, dotnetdiag<hex>.exe on Windows), fs.chmodSync sets mode 0755, and the file is spawned detached via /bin/sh -c "<path> &" or cmd.exe /c start /b <path>. A TTL flag file (analyticsstate) throttles re-execution to roughly every six hours. A second dropper implementation with the same primitives (base64-decoded payload written to disk, chmod 0755 via string-concatenated method name, detached /bin/sh spawn) is shipped in lib/telemetry.js. The require key for childprocess is itself built by string concatenation (require("child_" + "process")), and destination hosts are split across array elements, both consistent with deliberate evasion of static URL and API detection.

Database specific 
{
    "malicious-packages-origins": [
        {
            "versions": [
                "35.2.8"
            ],
            "modified_time": "2026-08-05T14:13:35Z",
            "import_time": "2026-08-05T14:20:13.65577405Z",
            "id": "IN-MAL-2026-015216",
            "source": "amazon-inspector",
            "sha256": "9e7a07623c75a85bada6117a7a71f40d19924be192a769534e544ffe31f036b0"
        }
    ]
}
References
Credits

Affected packages

npm / checkout-desktop-legal

Package

Name
checkout-desktop-legal
View open source insights on deps.dev
Purl
pkg:npm/checkout-desktop-legal

Affected ranges

Affected versions

35.*
35.2.8

Database specific

cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-desktop-legal/MAL-2026-12557.json"
indicators 
{
    "package_integrity": [
        {
            "filename": "checkout-desktop-legal-35.2.8.tgz",
            "hashes": {
                "sha512_sri": "sha512-Iz1ruqvDK4mRUmyLR3dsa+7mPK2w7xiepo1N3fPxaGZm30HaI0Ykb/ZApp7Ybfkfbo/ABIHynFH3vZavybMPpg==",
                "sha1": "1c3d600ed631e2d9a7bc677d270033aebbc64ec1"
            }
        }
    ],
    "evidence_files": [
        {
            "sha256": "48bbff69f23c8feb713b60686aca21206365fe9c6c313e175b5ab234c58337cf",
            "path": "_compat.js",
            "tlsh": "20a1866a166670184770d7e5ca175416f66af6637380c2c8fb9c698c1ff222482b2efc"
        },
        {
            "sha256": "70d1bd882ee0f2ea8289d131dbdaa06e6dcf2aad342cc47fdbf130a602976859",
            "path": "lib/telemetry.js",
            "tlsh": "53835055566a242186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"
        }
    ]
}