MAL-2026-13525

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-security/MAL-2026-13525.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13525
Published
2026-08-07T12:24:34Z
Modified
2026-08-07T13:20:14.239745978Z
Summary
Malicious code in bigops-security (npm)
Details

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

Source: amazon-inspector (f4eccfe477123e2d048f10c141165dec00f0ce2bfe28b7b9611a189fc63f0384)

On require('bigops-security'), index.js loads bridge.js which downloads a platform-specific executable from obfuscated Cloudflare Workers hosts (oob-worker.cf10{0..3}-*.workers.dev) with a DNS-TXT chunked-base64 fallback via *.dl.wel1.ru subdomains. Destination hostnames are reconstructed at runtime from split string arrays (e.g. ['sdk','.dl.','wel1.','ru'].join('')) rather than appearing as plain literals. The fetched bytes are written to /tmp or %TEMP% under disguised names such as dotnetdiag<hex>.exe and.cache<hex>, chmod 755'd, and detach-spawned via spawn('/bin/sh',...) or spawn('cmd',...) at _bridge.js:121-127. Cover-story identifiers ("analytics", "telemetry", "CDN", "Respect opt-out") frame the code as benign while the actual behavior is fetch-and-execute of an opaque binary from author-controlled infrastructure. No native-build purpose is present in the tarball; the package advertises itself as a security module.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "f4eccfe477123e2d048f10c141165dec00f0ce2bfe28b7b9611a189fc63f0384",
            "source": "amazon-inspector",
            "modified_time": "2026-08-07T12:24:34Z",
            "versions": [
                "35.8.8"
            ],
            "import_time": "2026-08-07T12:51:20.183407555Z",
            "id": "IN-MAL-2026-016968"
        }
    ]
}
References
Credits

Affected packages

npm / bigops-security

Package

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

Affected ranges

Affected versions

35.*
35.8.8

Database specific

indicators 
{
    "package_integrity": [
        {
            "hashes": {
                "sha1": "6f4edd0c585317035ebf5bb09715892132240aad",
                "sha512_sri": "sha512-zpV3iSE91mk6LFCI44JVnqW536wB9WYDRiir2NSWqtprCCbDio5hBaFwqgVER2Y9EKfXEPuF0l0jXtSil3n+Aw=="
            },
            "filename": "bigops-security-35.8.8.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_bridge.js",
            "sha256": "8744adb7c670453f85aa1ddf3958f0aac76407860f14adc65e685bcee2c6ec18",
            "tlsh": "5ab1a79616aa711987b0d7e487174416f69ae7633380c6d8fb6ca8885f73128c3b1dfc"
        }
    ]
}
cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-security/MAL-2026-13525.json"