MAL-2026-13223

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-logs-player/MAL-2026-13223.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13223
Published
2026-08-05T15:38:12Z
Modified
2026-08-05T16:49:59.778100381Z
Summary
Malicious code in bigops-logs-player (npm)
Details

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

Source: amazon-inspector (f5a922558781f9614bc47976e2e695cc8a5996ef51865fb5b37928f842718b5d)

On require() of bigops-logs-player, index.js loads polyfill.js, which reconstructs a list of Cloudflare Workers hostnames (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) from split string fragments to hide them from static scanners. It downloads an OS-specific native binary via https.get, writes it to /tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnetdiag<hex>.exe on Windows), chmods it 0o755, and spawns it detached through /bin/sh or cmd.exe. A DNS-TXT covert-channel fallback resolves alternate hosts under *.dl.wel1.ru (also assembled from split fragments). A freshness marker and environment opt-outs gate execution to reduce noise. The package advertises itself as a log-transport library; fetching and executing a native binary from obfuscated attacker-controlled infrastructure has no relation to that purpose.

Database specific 
{
    "malicious-packages-origins": [
        {
            "modified_time": "2026-08-05T15:38:12Z",
            "sha256": "f5a922558781f9614bc47976e2e695cc8a5996ef51865fb5b37928f842718b5d",
            "id": "IN-MAL-2026-015774",
            "versions": [
                "35.2.8"
            ],
            "source": "amazon-inspector",
            "import_time": "2026-08-05T16:13:43.82258511Z"
        }
    ]
}
References
Credits

Affected packages

npm / bigops-logs-player

Package

Name
bigops-logs-player
View open source insights on deps.dev
Purl
pkg:npm/bigops-logs-player

Affected ranges

Affected versions

35.*
35.2.8

Database specific

cwes 
[
    {
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature."
    }
]
indicators 
{
    "evidence_files": [
        {
            "tlsh": "4aa1845a02a970194bb0dbe4ca175816f65bfa633780c284fb5ca5881f73624c372dfc",
            "sha256": "99f4b7d6888357234da5953efd1521ab427958ecf77681536a9ab7aebdff94f7",
            "path": "_polyfill.js"
        }
    ],
    "package_integrity": [
        {
            "filename": "bigops-logs-player-35.2.8.tgz",
            "hashes": {
                "sha512_sri": "sha512-Kf/7Zt4KdZATTgDsI51oqNZV6UW2nbujFgumWAL/kcA7/7SbkZoEEmxrRoqnTUPNEaFKqZuEbMRBvENS67p84g==",
                "sha1": "9b4645c93400ada7241e4252f824dd3adab149e8"
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-logs-player/MAL-2026-13223.json"