MAL-2026-12646

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-use-base-analytics/MAL-2026-12646.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12646
Published
2026-08-05T13:59:46Z
Modified
2026-08-05T14:36:05.898967562Z
Summary
Malicious code in claims-use-base-analytics (npm)
Details

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

Source: amazon-inspector (0f191811e6841cbfe4cc2c9621f7876290b92efc2bdc78e9c4f6c4cca7933c0f)

claims-use-base-analytics@35.4.9 is a native-binary dropper disguised as an analytics wrapper. On require, index.js loads shim.js which selects a platform-specific asset path and fetches an opaque binary via HTTPS from one of three attacker-controlled Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev). The binary is written to /tmp or %TEMP% under a disguised name (e.g. dotnetdiag<rnd>.exe on Windows,.cache<rnd> on Unix), chmod 0755, and spawned detached via /bin/sh -c or cmd /c start /b. If the HTTPS fetch fails, loadViaDns() reassembles a base64-encoded payload from TXT records under per-platform subdomains of dl.wel1.ru (sdk., ext., pkg., net.) — a DNS-over-TXT covert channel designed to bypass HTTP egress filtering — then writes, chmods, and executes the resulting bytes. C2 hostnames are string-split-obfuscated (e.g. ["oob-worker.cf100-416.w","orke","rs",".dev"].join("")) and require("child_" + "process") is used to evade static analysis. Execution is gated by a ~6h TTL cache stamp in.analyticsstate so it fires at most once per interval, and DISABLETELEMETRY / DONOTTRACK env vars are honored as cover for an ostensibly benign analytics stub. The package's advertised purpose (analytics wrapper) has no legitimate need for a native-binary dropper, a covert DNS-TXT fallback, or hostname obfuscation.

Database specific 
{
    "malicious-packages-origins": [
        {
            "sha256": "0f191811e6841cbfe4cc2c9621f7876290b92efc2bdc78e9c4f6c4cca7933c0f",
            "id": "IN-MAL-2026-015122",
            "modified_time": "2026-08-05T13:59:46Z",
            "source": "amazon-inspector",
            "import_time": "2026-08-05T14:20:04.355822731Z",
            "versions": [
                "35.4.9"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / claims-use-base-analytics

Package

Name
claims-use-base-analytics
View open source insights on deps.dev
Purl
pkg:npm/claims-use-base-analytics

Affected ranges

Affected versions

35.*
35.4.9

Database specific

indicators 
{
    "evidence_files": [
        {
            "sha256": "98f42b81ae02d895df3375c9379bb0f446284296ba430627a9cf905566392b48",
            "path": "_shim.js",
            "tlsh": "e9a185aa15a6701847b0dbe4c6176415f65bf6633780c1d8fb9ca5d80fb326482b2efc"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-R7Ke3XNnDl8GZpt1/p5E/sxe9NRoV+/l5kGT79ZEXLAr1D/3nyge0VE0B6CthaI2tmgZiaYKMZFG0hQNBFkIDQ==",
                "sha1": "f5ac20435f8ca5bc5719db01e95933b3c1e6b47b"
            },
            "filename": "claims-use-base-analytics-35.4.9.tgz"
        }
    ]
}
cwes 
[
    {
        "name": "Embedded Malicious Code",
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506"
    }
]
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-use-base-analytics/MAL-2026-12646.json"