MAL-2026-12037

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-create-manifest/MAL-2026-12037.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12037
Published
2026-08-05T01:35:33Z
Modified
2026-08-05T01:49:48Z
Summary
Malicious code in bigops-create-manifest (npm)
Details

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

Source: amazon-inspector (027d25851cc38da61b10c0ce1d722d3e8455826d2f7866474432e98dd8f1b806)

On require, index.js loads polyfill.js which selects a platform-specific endpoint, downloads an opaque native binary over HTTPS from one of several Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS TXT covert-channel fallback that reads base64-encoded chunks from sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to a randomized filename disguised as dotnet_diag.exe on Windows or.cache_ under /var/tmp on Unix, chmod 0755, and spawned detached via /bin/sh -c or cmd. C2 hostnames and resolver domains are assembled at runtime via split-string array joins; artifact naming, an analytics_state marker, and DISABLE_TELEMETRY env checks frame the operation as diagnostics. The package's advertised purpose (a manifest wrapper) has no need for downloading and executing a native binary from third-party infrastructure.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-011505",
            "import_time": "2026-08-05T01:39:31.959956153Z",
            "modified_time": "2026-08-05T01:35:33Z",
            "sha256": "027d25851cc38da61b10c0ce1d722d3e8455826d2f7866474432e98dd8f1b806",
            "source": "amazon-inspector",
            "versions": [
                "35.2.4"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / bigops-create-manifest

Package

Name
bigops-create-manifest
View open source insights on deps.dev
Purl
pkg:npm/bigops-create-manifest

Affected ranges

Affected versions

35.*
35.2.4

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": "_polyfill.js",
            "sha256": "4a0b469a1ee7e087dae0e187924dc54c24aa734fb93d1478d5e942502b4cb3e0",
            "tlsh": "19b1a69a026670154b70e7e4c71b481af55af6633781c298f75c65984fb352483b2efc"
        }
    ],
    "package_integrity": [
        {
            "filename": "bigops-create-manifest-35.2.4.tgz",
            "hashes": {
                "sha1": "f71c48100997ed951c00e9d08a5b879b3dd6fc46",
                "sha512_sri": "sha512-kxsC9iagMwEykN3VS7yTxaoCDhSWK47UcrJ7JNIzapHVtvyP3/FYtpqiDOyi4GpNQhquT3Le7OAmtj4dHBgEPw=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-create-manifest/MAL-2026-12037.json"