MAL-2026-12633

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-payout-offer-api-adapters/MAL-2026-12633.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12633
Published
2026-08-05T14:03:01Z
Modified
2026-08-05T14:35:58.619654712Z
Summary
Malicious code in claims-payout-offer-api-adapters (npm)
Details

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

Source: amazon-inspector (850a478885db918edfa4d7ae8131202acf806c8baa7e2c973b6a5c05735b6918)

On require() of the package's main entry, index.js loads support.js which downloads a platform-specific binary from split/obfuscated Cloudflare Workers hostnames (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT base64 fallback across numbered subdomains of dl.wel1.ru. The fetched binary is written to a temp path with a deceptive name (dotnetdiag<hex>.exe /.cache<hex>), chmod 0755 on Unix, and spawned detached via cmd.exe or /bin/sh -c with.unref(). Hostnames are reconstructed at runtime via Array.join("") of split fragments to evade static analysis. There is no version pin, hash check, or signature verification on the downloaded bytes, and the delivery hosts are not the package's publisher domain. The fetch-and-execute chain fires unconditionally on import unless specific env vars are set, so any consumer that installs and requires this package auto-runs attacker-controlled code.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "850a478885db918edfa4d7ae8131202acf806c8baa7e2c973b6a5c05735b6918",
            "id": "IN-MAL-2026-015143",
            "modified_time": "2026-08-05T14:03:01Z",
            "source": "amazon-inspector",
            "import_time": "2026-08-05T14:20:06.507583115Z",
            "versions": [
                "35.2.2"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / claims-payout-offer-api-adapters

Package

Name
claims-payout-offer-api-adapters
View open source insights on deps.dev
Purl
pkg:npm/claims-payout-offer-api-adapters

Affected ranges

Affected versions

35.*
35.2.2

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "b79c0c908d8b55a8f27449163fe1178db3076f2796ce7df67137fbbe2c4d2fec",
            "path": "_support.js",
            "tlsh": "89a1965a16aa70198bb0d7e48717441af66ee66333c0c2d4f79ca9985f72124c3b2dfc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-6VnDEiEjWBLqsdAS4VjhKrYNptwv/LD2wAacdJKhmpqxPLzyX5myf0yIHB5Wa0byPG9sGv6QOU5HzMFwLDz1KA==",
                "sha1": "05d13090358d80c45f5471905e5bf8a9a088dd2a"
            },
            "filename": "claims-payout-offer-api-adapters-35.2.2.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-payout-offer-api-adapters/MAL-2026-12633.json"