MAL-2026-12595

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-test-component/MAL-2026-12595.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12595
Published
2026-08-05T14:08:28Z
Modified
2026-08-05T14:35:40Z
Summary
Malicious code in checkout-test-component (npm)
Details

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

Source: amazon-inspector (c8dff84319052d8da1a322df80332f9d197a3e646f17c15b2fb5b53121f27dc0)

On require() of the package, index.js loads./runtime.js which unconditionally fetches a platform-specific executable from attacker-controlled Cloudflare Workers hosts (oob-worker.cf*.workers.dev) with a DNS/TXT fallback to *.dl.wel1.ru, writes it to /var/tmp or %TEMP% under cover-story names (.cache, dotnet_diag_.exe, analytics_state), chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe. Destination hostnames are constructed by fragment-and-.join("") to evade static analysis. A secondary dropper implementation is shipped as lib/telemetry.js (~81 KB) using base64 chunk decoding, cp.spawn("/bin/sh", ["-c", filePath + " &"]), and fs["chmod"+"Sync"] with 0755, framed as an analytics.node SDK — duplicating the dropper mechanism as a dormant secondary payload. The package name resembles a benign test/checkout utility but contains no such functionality; its sole effect on load is to drop and execute attacker-controlled code on the installer's host.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015181",
            "import_time": "2026-08-05T14:20:10.290587113Z",
            "modified_time": "2026-08-05T14:08:28Z",
            "sha256": "c8dff84319052d8da1a322df80332f9d197a3e646f17c15b2fb5b53121f27dc0",
            "source": "amazon-inspector",
            "versions": [
                "35.9.8"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / checkout-test-component

Package

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

Affected ranges

Affected versions

35.*
35.9.8

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": "_runtime.js",
            "sha256": "3d60c6dc5b4b45ea8d6f54ab5fa1e8c00b0bbcb5a5fe8cbc2457976385ab2ec6",
            "tlsh": "f7b1859a01a671188bb0dbe4871b8816f65bf6633280c6c4f79c69945f77124c2b2efc"
        },
        {
            "path": "lib/telemetry.js",
            "sha256": "c14e2228752a21af81ab3e84f5c1e55acc9932e7276baa7a2fddc9787b75b014",
            "tlsh": "e4835056566a142186b2b368df234107ff3685272642429dbafc82dc1fbd72092a5ffc"
        }
    ],
    "package_integrity": [
        {
            "filename": "checkout-test-component-35.9.8.tgz",
            "hashes": {
                "sha1": "f69fbcf806d0695c3c3d9571e4ddba7c85b73ab0",
                "sha512_sri": "sha512-MbHcAGcqau5bpRL14PWOKF0MWTak4vkvixuF2wX0ZeMqtJYoHnAzPPXgnlcJGEGG0mc67qk5etNBj0Gvex6NvQ=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-test-component/MAL-2026-12595.json"