MAL-2026-12665

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/contract-contract-builder/MAL-2026-12665.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12665
Published
2026-08-05T13:58:51Z
Modified
2026-08-05T14:36:14.656032933Z
Summary
Malicious code in contract-contract-builder (npm)
Details

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

Source: amazon-inspector (3758ab87194c554acffc80e8cd2caf8fa8890e92854115edab08615877f22b5f)

On require() of the package, platform.js downloads a platform-specific binary from Cloudflare Workers hosts whose names are assembled at runtime from split string fragments (oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev). The fetched bytes are written to /tmp or %TEMP% under disguising names (.cache<hex> on POSIX, dotnetdiag<hex>.exe on Windows), chmodded 0755, and spawned detached via cp.spawn("/bin/sh", ["-c", fp+" &"], {detached:true}) or the Windows equivalent. A DNS-TXT fallback channel under *.dl.wel1.ru reassembles a base64 payload from numbered TXT records (c.<domain>, 0.<domain>, 1.<domain>,...) when HTTPS delivery fails. The package advertises itself as a UI toolkit; the fetched binary is unrelated to that purpose, unpinned, unverified, and executed on import.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015117",
            "import_time": "2026-08-05T14:20:03.835543125Z",
            "sha256": "3758ab87194c554acffc80e8cd2caf8fa8890e92854115edab08615877f22b5f",
            "modified_time": "2026-08-05T13:58:51Z",
            "versions": [
                "35.5.2"
            ],
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / contract-contract-builder

Package

Name
contract-contract-builder
View open source insights on deps.dev
Purl
pkg:npm/contract-contract-builder

Affected ranges

Affected versions

35.*
35.5.2

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-s+TL/tIAm+JiI4m5169sgfVWQBlrQWjJhOYyiEFo4WQNmrEGAENsQWEJAbD/d23P3gjO4R33D3E3ju2sXIXlow==",
                "sha1": "85b17bb10fa7f3776ca6a5e794645f9ff4a5dd6c"
            },
            "filename": "contract-contract-builder-35.5.2.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_platform.js",
            "sha256": "847545fac36267fd125c40480b2bbfc75cb83ac391fd85515ede82446c865fee",
            "tlsh": "06a1856a11a570188bb0dbe1c2176416f66bf6632281c5d4f69c69d80ff622483b3efc"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/contract-contract-builder/MAL-2026-12665.json"