MAL-2026-12613

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-domain/MAL-2026-12613.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12613
Published
2026-08-05T14:05:44Z
Modified
2026-08-05T14:35:49.645900646Z
Summary
Malicious code in claims-domain (npm)
Details

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

Source: amazon-inspector (f75c174b3db5e2480eabc7c7f8ab5e8366737fac8e76086da13f8acac6545813)

On require of the package, index.js loads _ext.js, which reconstructs destination hostnames from string-split arrays (e.g. ["oob-worker.cf99-9b3",".wor","kers.","dev"].join("")) to build URLs at oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, and oob-worker.cf102-baf.workers.dev, with a DNS TXT fallback to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched platform-specific binary is written to /var/tmp or the Windows temp directory under disguised filenames (.cache_<hex>, dotnet_diag_<hex>.exe), chmodded to 0755, and spawned detached via /bin/sh -c or cmd /c start. The child_process module and fs.chmodSync API are also referenced through string concatenation (require("child_" + "process"), fs["chmod" + "Sync"]) alongside cover-story comments describing the routine as an analytics/telemetry SDK. The package's advertised purpose (a claims-domain library) does not require fetching or executing native binaries from anonymous Cloudflare Workers subdomains, and the delivery is unpinned, unhashed, and obfuscated.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "f75c174b3db5e2480eabc7c7f8ab5e8366737fac8e76086da13f8acac6545813",
            "id": "IN-MAL-2026-015161",
            "modified_time": "2026-08-05T14:05:44Z",
            "source": "amazon-inspector",
            "import_time": "2026-08-05T14:20:08.305279533Z",
            "versions": [
                "35.6.7"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / claims-domain

Package

Name
claims-domain
View open source insights on deps.dev
Purl
pkg:npm/claims-domain

Affected ranges

Affected versions

35.*
35.6.7

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "fc945fa7bb70385b7660edb2464d02ebfb8510cd1f7a4b11e357998b5ffa29e3",
            "path": "_ext.js",
            "tlsh": "5db1b69a126670198bb09bf0c717581af65be6633780c2d8f75c69981fb612483b1efc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-CukXb45ZO/uXhCPV2Oh8y4Ksl2qSLIEHeM7hxh55aepNa7yUWRoHzDFnK2la1GQTD9IpVUWxsIgTwa5PymW5+Q==",
                "sha1": "11d42dc900bb6f69f01b8502887b96827738c8ec"
            },
            "filename": "claims-domain-35.6.7.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/claims-domain/MAL-2026-12613.json"