MAL-2026-13229

See a problem?
Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-opening-file-handler/MAL-2026-13229.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13229
Published
2026-08-05T15:37:01Z
Modified
2026-08-05T16:50:02Z
Summary
Malicious code in bigops-opening-file-handler (npm)
Details

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

Source: amazon-inspector (9c423840bea5711af66c8f9c24eca1c406a4fa929dc6b9e9d947ec71ea5adc39)

On require of bigops-opening-file-handler, index.js loads support.js which selects a platform-specific asset (linux/darwin/win32) and downloads an opaque native binary from one of four hardcoded Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), with a DNS-TXT discovery fallback under *.dl.wel1.ru (e.g. sdk.dl.wel1.ru). The hostnames are reassembled at runtime from string arrays via.join('') to evade static matching. The fetched bytes are written to /var/tmp or %TEMP% under disguised names such as.cache or dotnet_diag_.exe, chmodded 0755, and spawned detached via /bin/sh -c or cmd. The package advertises itself as a file-handler abstraction; the delivered payload is unrelated native code from author-controlled infrastructure, executed automatically when the module is required.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015767",
            "import_time": "2026-08-05T16:13:42.924541564Z",
            "modified_time": "2026-08-05T15:37:01Z",
            "sha256": "9c423840bea5711af66c8f9c24eca1c406a4fa929dc6b9e9d947ec71ea5adc39",
            "source": "amazon-inspector",
            "versions": [
                "35.9.2"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / bigops-opening-file-handler

Package

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

Affected ranges

Affected versions

35.*
35.9.2

Database specific

cwes 
[
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files": [
        {
            "path": "_support.js",
            "sha256": "e493e0d9ef8be2aa73b7bbc3cfc455833b14d698185fb57b3488952a2f0da170",
            "tlsh": "9bb1765a16a670184f70e7e4c61b4816f66bf6633680c2c4fb9ca5945f7352882b2efc"
        }
    ],
    "package_integrity": [
        {
            "filename": "bigops-opening-file-handler-35.9.2.tgz",
            "hashes": {
                "sha1": "f21da25e4bcdf29428eed451a402d6f8236f620a",
                "sha512_sri": "sha512-FAufdbwSiu4n8T7gTgkk7n0ACacR2FEsnBzGVz+5R2rC2cvyMKHOG75ZYpFga5P2PbHt+8BV92090sWbRAkvqw=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-opening-file-handler/MAL-2026-13229.json"