MAL-2026-12602

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/checkout-use-notifications/MAL-2026-12602.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12602
Published
2026-08-05T14:07:07Z
Modified
2026-08-05T14:35:44.459138057Z
Summary
Malicious code in checkout-use-notifications (npm)
Details

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

Source: amazon-inspector (1a9b7cb00a4aac61795c81a085319cb8b0ac0aff1350a0dafddb4ef31d25a15f)

On require of the package, index.js unconditionally loads shim.js, which fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev) with a DNS TXT-record fallback channel via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. Hostnames are assembled at runtime by joining split string fragments to evade static detection. The fetched payload is written to /tmp or %TEMP% under disguised names (.cache<rand>, dotnetdiag<rand>.exe), chmod 0755 on Unix, and spawned detached via /bin/sh -c or cmd with stdio ignored. The DNS fallback base64-decodes numbered TXT chunks to reconstruct the payload when HTTPS fetches fail. An anti-re-run stamp gates repeated execution. The delivery infrastructure, string-split hostname obfuscation, disguised on-disk filenames, and DNS covert channel are canonical malicious dropper fingerprints.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "1a9b7cb00a4aac61795c81a085319cb8b0ac0aff1350a0dafddb4ef31d25a15f",
            "id": "IN-MAL-2026-015171",
            "modified_time": "2026-08-05T14:07:07Z",
            "import_time": "2026-08-05T14:20:09.32905207Z",
            "source": "amazon-inspector",
            "versions": [
                "35.6.1"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / checkout-use-notifications

Package

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

Affected ranges

Affected versions

35.*
35.6.1

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "d331a36097697d8b731039cdfbd48b6f90fb9c60c44847372d889787db75cd5b",
            "path": "_shim.js",
            "tlsh": "97a1a85a1666701887b09be5c7274419f95bf2633780c294fb9ca5981fb35248372dfc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-Xv/xqugpoRsnJML/Py+C2KgzYyBXdS7fG4nsOFoPBwNq4ub8PwZ1F/YwtWzJ6ERBivPYn8qmoyQoMg5YsZ0TqA==",
                "sha1": "0d903232516a6e0012136cb64c5936515ae923d1"
            },
            "filename": "checkout-use-notifications-35.6.1.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/checkout-use-notifications/MAL-2026-12602.json"