MAL-2026-13013

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bnpl-blocks-post-css/MAL-2026-13013.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-13013
Published
2026-08-05T14:37:04Z
Modified
2026-08-05T15:51:42.168102022Z
Summary
Malicious code in bnpl-blocks-post-css (npm)
Details

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

Source: amazon-inspector (dd5d8d3c9328912323fee5066e4c32c14904ec3e8b1800f66da0d1749babda0c)

On require(), polyfill.js reconstructs attacker-controlled hostnames from string-split fragments (oob-worker.cf103-070.workers.dev, with a DNS-TXT fallback via sdk.dl.wel1.ru), downloads a platform-specific native binary, 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 via spawn('/bin/sh', ['-c', <path> + ' &'], {detached:true}) or the cmd equivalent. lib/telemetry.js contains a second implementation of the same fetch->write->chmod 755->spawn pattern with a base64-decoded payload under an analytics-SDK cover story. The package is advertised as a CSS-blocks utility and has no legitimate reason to fetch and execute native binaries; the string-split obfuscation of the download hosts and the 'analyticsstate' / DISABLETELEMETRY cover-story naming further confirm hostile intent.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-08-05T15:19:47.689527945Z",
            "sha256": "dd5d8d3c9328912323fee5066e4c32c14904ec3e8b1800f66da0d1749babda0c",
            "id": "IN-MAL-2026-015372",
            "modified_time": "2026-08-05T14:37:04Z",
            "source": "amazon-inspector",
            "versions": [
                "35.5.4"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / bnpl-blocks-post-css

Package

Name
bnpl-blocks-post-css
View open source insights on deps.dev
Purl
pkg:npm/bnpl-blocks-post-css

Affected ranges

Affected versions

35.*
35.5.4

Database specific

source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bnpl-blocks-post-css/MAL-2026-13013.json"
indicators 
{
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-X59NXgBgFgtYqPxU4cVtBd8Y9Iwfx6/39G0p5jBhGQtl0vKdIerOTTFJbgiVVKUT2vtMsMw/68rRcqlERv/myQ==",
                "sha1": "0db04fccaafc7ea39da1d13d89a27c611255f7c1"
            },
            "filename": "bnpl-blocks-post-css-35.5.4.tgz"
        }
    ],
    "evidence_files": [
        {
            "sha256": "750768dd04b7c0d519ef4f31d34f1c6781d8ef7f4c7b7debd69a0513d4f37d37",
            "path": "_polyfill.js",
            "tlsh": "8ea1b5aa05a760098b70d7e5c7175416f65bf6633380c288fb5ca5980fb252883b2efc"
        },
        {
            "sha256": "46ecb896f377b9cef773e43a2e408828ee71631e2c4eb3340e9b2acffe558d0d",
            "path": "lib/telemetry.js",
            "tlsh": "ae835056566a142186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"
        }
    ]
}
cwes 
[
    {
        "description": "The product contains code that appears to be malicious in nature.",
        "cweId": "CWE-506",
        "name": "Embedded Malicious Code"
    }
]