MAL-2026-12663

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/constructor-blocks-renderer-landings/MAL-2026-12663.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12663
Published
2026-08-05T13:57:52Z
Modified
2026-08-05T14:36:13.614777154Z
Summary
Malicious code in constructor-blocks-renderer-landings (npm)
Details

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

Source: amazon-inspector (30760e14810ab84bc5a33ca63171101f0f3b23d044a74a58eb9ab5a0038ae01a)

On import, the package's main entry (index.js) unconditionally loads polyfill.js, which fetches a platform-specific executable from one of four hardcoded Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev) assembled via runtime string-joining, writes it to /var/tmp or %TEMP% under cover-story filenames (.cache<hex>, dotnetdiag<hex>.exe), chmods it to 0755, and spawns it detached via /bin/sh -c or cmd. A DNS-TXT covert-channel fallback under *.dl.wel1.ru retrieves the payload as chunked base64 when the HTTPS fetch is blocked. A second, structurally identical dropper module is bundled at lib/telemetry.js using split-string require("child_" + "process") and the same download-chmod-spawn shape. Host strings, module names, and API names are split-and-joined at runtime to defeat static analysis.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015110",
            "import_time": "2026-08-05T14:20:03.040246152Z",
            "sha256": "30760e14810ab84bc5a33ca63171101f0f3b23d044a74a58eb9ab5a0038ae01a",
            "modified_time": "2026-08-05T13:57:52Z",
            "versions": [
                "35.2.5"
            ],
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / constructor-blocks-renderer-landings

Package

Name
constructor-blocks-renderer-landings
View open source insights on deps.dev
Purl
pkg:npm/constructor-blocks-renderer-landings

Affected ranges

Affected versions

35.*
35.2.5

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": "sha512-8tkO0dsKCmOLfwcDXDvr/nUIvfmVDERk1Y5wtVTsFXFKg+lVB7MFZiymQq69eEvfuiWXzwccVcAHUKfyUyC+JA==",
                "sha1": "b73b0649902a3af3aa4fcd5c9e4332ff6ccf7856"
            },
            "filename": "constructor-blocks-renderer-landings-35.2.5.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_polyfill.js",
            "sha256": "9da937306902b4d8baf88981adec4e2db68ed0f3e7e4bd9847ef4807c2f02610",
            "tlsh": "6ca1a9aa16aa70184bb0d7e4c7175416f55bf7633380c289f75c59981f7302482b2efc"
        },
        {
            "path": "lib/telemetry.js",
            "sha256": "031fdb9c9dbf47fa34867f53a9ba4c69f12dd7706d376cc29d18238b27206ea7",
            "tlsh": "b5835055566a202186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffd"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/constructor-blocks-renderer-landings/MAL-2026-12663.json"