MAL-2026-12650

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/cnb-cnb-core/MAL-2026-12650.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12650
Published
2026-08-05T14:00:22Z
Modified
2026-08-05T14:36:08.048800382Z
Summary
Malicious code in cnb-cnb-core (npm)
Details

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

Source: amazon-inspector (6d98cce19255e9c794f6211b2af4feb078a17256448ef693fbdb31cb1de27b97)

On require('cnb-cnb-core'), index.js loads shim.js which downloads a platform-specific executable from string-obfuscated hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev), writes it to /tmp or %TEMP% under decoy names (.cache<rand>, dotnetdiag<rand>.exe), chmods 0755, and spawns it detached via cp.spawn('/bin/sh', ['-c', fp+' &'], {detached:true, stdio:'ignore'}) or spawn('cmd',...). When HTTP fetch fails, shim.js falls back to a DNS-TXT covert channel under *.dl.wel1.ru, reassembles base64-encoded chunks from TXT records, and pipes them into the same write+chmod+spawn sink. Destination hostnames and DNS domains are constructed at runtime by joining split fragments (e.g., ['oob-work','er','.cf103-070.worker','s.','dev'].join('')) to defeat static scanners. Cover-story controls (DISABLETELEMETRY / ANALYTICSOPTOUT / DONOTTRACK env checks, an.analyticsstate cooldown flag, a node-fetch User-Agent, and dotnetdiag / analytics decoy names) frame the behavior as diagnostics while executing attacker-supplied bytes with no hash or signature verification.

Database specific 
{
    "malicious-packages-origins": [
        {
            "id": "IN-MAL-2026-015126",
            "import_time": "2026-08-05T14:20:04.72319669Z",
            "sha256": "6d98cce19255e9c794f6211b2af4feb078a17256448ef693fbdb31cb1de27b97",
            "modified_time": "2026-08-05T14:00:22Z",
            "versions": [
                "35.2.7"
            ],
            "source": "amazon-inspector"
        }
    ]
}
References
Credits

Affected packages

npm / cnb-cnb-core

Package

Name
cnb-cnb-core
View open source insights on deps.dev
Purl
pkg:npm/cnb-cnb-core

Affected ranges

Affected versions

35.*
35.2.7

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-mlpHWSGGqjwUmrU+Eo4v/opryca2khMOrqWWi+If1jfb+jY51eJkuL7KnipL6vnYnActTsKHdkptfvPIAswaNA==",
                "sha1": "4b5770779677c12abcb187d16e9dc7f5443996db"
            },
            "filename": "cnb-cnb-core-35.2.7.tgz"
        }
    ],
    "evidence_files": [
        {
            "path": "_shim.js",
            "sha256": "deaa0c7c9a1ebb81830178f90fbd47b0e12cccc32ada78962d2b36ea9a6e38f4",
            "tlsh": "48a197aa166670184b70d7e4c61b5816f55bf6637380c194fb9c99984ff212482b2efc"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/cnb-cnb-core/MAL-2026-12650.json"