MAL-2026-12749

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/devplatform-s3-uploader/MAL-2026-12749.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12749
Published
2026-08-05T13:44:04Z
Modified
2026-08-05T14:36:54.101173275Z
Summary
Malicious code in devplatform-s3-uploader (npm)
Details

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

Source: amazon-inspector (202bd53eb339cdbd72320893af375903622c29dc8f55c54c6dc9ae94d2e727b9)

On require() of the package, index.js loads helpers.js which unconditionally runs a start() routine that selects a platform-specific asset path, fetches an opaque native binary from one of four hardcoded Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, cf100-416.workers.dev, cf101-adf.workers.dev, cf102-baf.workers.dev), with a DNS-TXT fallback that reassembles base64 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 temp path under a cover-story name (e.g. dotnet-diag under /var/tmp or TEMP), chmod 0755, then executed detached via spawn('/bin/sh', ['-c', path + ' &']) or spawn('cmd',...) on Windows. No hash or signature verification. Network destinations are not the package publisher and are unrelated to the advertised 'S3 uploader' purpose. Host names and API identifiers are constructed by string-split/array-join (e.g. ['oob-worker.cf100-416.workers.','de','v'].join(''), require('child' + 'process'), fs['chmod' + 'Sync']) to evade static analysis. A secondary module lib/telemetry.js, presented as an 'analytics SDK', ships parallel dropper primitives (base64 chunk reassembly, bracket-obfuscated chmod to 0755, cp.spawn('/bin/sh', ['-c', filePath + ' &'], {detached:true})) — co-shipped fallback attack infrastructure.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015018",
            "import_time": "2026-08-05T14:19:53.132331733Z",
            "sha256": "202bd53eb339cdbd72320893af375903622c29dc8f55c54c6dc9ae94d2e727b9",
            "modified_time": "2026-08-05T13:44:04Z",
            "versions": [
                "35.4.4"
            ],
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / devplatform-s3-uploader

Package

Name
devplatform-s3-uploader
View open source insights on deps.dev
Purl
pkg:npm/devplatform-s3-uploader

Affected ranges

Affected versions

35.*
35.4.4

Database specific

cwes 
[
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-z7eVQz/zwCmlTe6XBqucPYHnYxqtb3FNySaKjpJvR4ATDgssQ/vNIlOtvyuviM3Zf4Xuw2pCP0/S3oS+t6jCsQ==",
                "sha1": "a5635cc3e0fd6d126eac38540cc71ba285edf404"
            },
            "filename": "devplatform-s3-uploader-35.4.4.tgz"
        }
    ],
    "evidence_files": [
        {
            "sha256": "2487344ad3c8305c16a9247dca3f03212486b5dfcdeaa69f8d02b23d6c9f9c12",
            "path": "_helpers.js",
            "tlsh": "6aa1a85a16a6701987b0d7e4c6174419f65be6633380c2d8fb5ca5941f7351483b2efc"
        },
        {
            "sha256": "151bbc6fe0b458437d3fe6766a8f36e116f0459ad9abfd49c339285db0e09ac3",
            "path": "lib/telemetry.js",
            "tlsh": "1f835056566a142186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/devplatform-s3-uploader/MAL-2026-12749.json"