MAL-2026-13201

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/dp-web-header/MAL-2026-13201.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13201
Published
2026-08-05T15:07:07Z
Modified
2026-08-05T15:53:10.747364759Z
Summary
Malicious code in dp-web-header (npm)
Details

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

Source: amazon-inspector (ec4c10894526621b93c3dba8f579e76be53db3989ab0ddb32c72bff180266786)

The package advertises itself as a web header library but its index.js unconditionally requires ext.js on load. ext.js downloads a platform-specific binary from hardcoded Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), writes it to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnetdiag<hex>.exe on Windows, chmods it 0755, and spawns it detached via spawn('/bin/sh',...) or spawn('cmd',...). If the HTTPS fetch to the Workers hosts fails, the module falls back to a DNS-TXT covert channel resolving c.<domain>, 0.<domain>, 1.<domain>,... under sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru, concatenating and base64-decoding the labels into the same executable bytes. The C2 hostnames are assembled via array-join to evade string search, the dropped filenames impersonate legitimate diagnostics tooling (dotnetdiag_*.exe,.cache_*), a marker file.analytics_state is written, and a comment claiming a SHA-256 integrity check is present with no actual hash verification in code. Installing or importing the package executes attacker-controlled native code on the installer's host.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015573",
            "import_time": "2026-08-05T15:19:58.557076068Z",
            "sha256": "ec4c10894526621b93c3dba8f579e76be53db3989ab0ddb32c72bff180266786",
            "modified_time": "2026-08-05T15:07:07Z",
            "versions": [
                "35.3.8"
            ],
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / dp-web-header

Package

Name
dp-web-header
View open source insights on deps.dev
Purl
pkg:npm/dp-web-header

Affected ranges

Affected versions

35.*
35.3.8

Database specific

cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-lISe4YXgA8xrS9+0xFzR+0BUyUXC3IUBI7miXXV3eXlqZkPUlrEULMtzDDWFkbW0Yl3szS9tRGEZFzNoZjLd9g==",
                "sha1": "9de64cf8a9f70a1c911c10b14f1e45513734a005"
            },
            "filename": "dp-web-header-35.3.8.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_ext.js",
            "sha256": "026ace94d3bfa2f76e3edb09f6eff5a206c345788b31a243111a4754665336e0",
            "tlsh": "4ca1959a16a670188bb0dbe4c7175416f65be6632780c5c4fb9ca4885fb322483b1efc"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/dp-web-header/MAL-2026-13201.json"