MAL-2026-12606

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-api-clients-shared/MAL-2026-12606.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12606
Published
2026-08-05T14:06:16Z
Modified
2026-08-05T14:35:45.888058704Z
Summary
Malicious code in claims-api-clients-shared (npm)
Details

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

Source: amazon-inspector (95f8c902163c7dda0fc907a90fc4a71fbc08fcd1574e8cfcee53915674109a86)

claims-api-clients-shared@35.1.9 advertises itself as a REST client wrapper, but index.js unconditionally requires shim.js, whose main() runs on load. On import, shim.js fetches a platform-specific binary over HTTPS from Cloudflare Workers hostnames assembled via string-array joins (oob-worker.cf99-9b3.workers.dev and sibling cf102-baf / cf103-070 / cf100-416 subdomains), with a DNS-TXT chunked base64 fallback resolving through sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched payload is written to a temp path under cover-story names (dotnetdiag<hex>.exe on Windows,.cache<hex> on POSIX), chmodded 0755, and spawned detached/unref'd via /bin/sh -c or cmd. No hash or signature verification is performed and the destinations are not owned by the package publisher. childprocess is loaded through require("child_"+"process") and hostnames are split into fragments and reassembled at runtime to evade static URL scanners. A separate lib/telemetry.js (~81 KB, unreferenced from index.js) mirrors the dropper's vocabulary (.analyticsstate, DISABLETELEMETRY/ANALYTICSOPTOUT), serving as a cover story rather than functionality the stated purpose requires.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "95f8c902163c7dda0fc907a90fc4a71fbc08fcd1574e8cfcee53915674109a86",
            "id": "IN-MAL-2026-015165",
            "modified_time": "2026-08-05T14:06:16Z",
            "import_time": "2026-08-05T14:20:08.626767618Z",
            "source": "amazon-inspector",
            "versions": [
                "35.1.9"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / claims-api-clients-shared

Package

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

Affected ranges

Affected versions

35.*
35.1.9

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "2e78d0b9a25cfb95543031942a0f5d156ca7b4d1fd101fa2d7aa6a9148ebb887",
            "path": "_shim.js",
            "tlsh": "93a1865a06aa70184bb0ebe4cb1b4819f65afa5337818284f79c69945f73514c3b2efc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-QGLqpTXXWXsnNi1mVw4YHpv1odNXH38SvsISEaQEoXfaqwrkrf93QvJIaBYHWOniZqdviYQG5hmOwNR6l28sEw==",
                "sha1": "c70900ffc3fb9566607ded52a2cdc245d1520671"
            },
            "filename": "claims-api-clients-shared-35.1.9.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-api-clients-shared/MAL-2026-12606.json"