MAL-2026-11141

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/lib-streak-math/MAL-2026-11141.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-11141
Published
2026-07-28T13:30:11Z
Modified
2026-07-28T14:37:02.632164108Z
Summary
Malicious code in lib-streak-math (npm)
Details

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

Source: amazon-inspector (06cd4f53bed50a86ce85bcd8ebcd672ae7e3c01926cac1efd7f3dcf152484267)

The package's main entry index.mjs presents itself as a math helper but contains a top-level async IIFE that runs on any require/import of the module. All network destinations, filesystem paths, subprocess names, and Node built-in module names are stored as integer arrays and reconstructed at runtime via a char-code decoder _D(a) = String.fromCharCode(...a.map((c,i)=>((c-_K[i%3])+256)%256)) with _K=[11,23,47], hiding fs/promises, path, child_process, and node-fetch from static inspection. Decoded, the block downloads https://f004.backblazeb2.com/file/dp8hbvocjd2fpza/helper.tar.gz into a hidden directory under AppData/Local/Microsoft/Windows/syscache/helper/, extracts it with tar -xzf, and executes the dropped payload. On Windows, the target user profile is located by scanning /mnt/c/Users (WSL), and a launcher env-setup.cmd is written into AppData/Roaming/Microsoft/Windows/Start Menu/Programs/Startup/ so the dropped vite.exe auto-launches on every login. On Linux, a background-service binary is written to the same hidden path, chmod 0o755d, and spawned with stdio: 'ignore', detached: true followed by .unref(), surviving the parent process. The package's advertised math-library purpose is unrelated to the code that actually runs on import.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-07-28T14:19:56.910544363Z",
            "modified_time": "2026-07-28T13:30:11Z",
            "sha256": "06cd4f53bed50a86ce85bcd8ebcd672ae7e3c01926cac1efd7f3dcf152484267",
            "id": "IN-MAL-2026-010874",
            "source": "amazon-inspector",
            "versions": [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / lib-streak-math

Package

Name
lib-streak-math
View open source insights on deps.dev
Purl
pkg:npm/lib-streak-math

Affected ranges

Affected versions

1.*
1.0.0

Database specific

indicators 
{
    "evidence_files": [
        {
            "path": "index.mjs",
            "tlsh": "f322628245b602b8e52adbd45a5f5019a2b1f01f3f568a847a8de3433f07c349676fac",
            "sha256": "d3c35c429dde7ce7789db727c146052a41524f031700726e19da0ae1fbdfdba4"
        }
    ],
    "package_integrity": [
        {
            "hashes": {
                "sha512_sri": "sha512-Y+aZLxPyK0QVca5oLwnPSiTep8DHd3YweMz0n8eIM3me+7GHw7eE/fT2YjEUtO2zxy1YJ9R//nbRTsm6RuGwvw==",
                "sha1": "2ecc72530857b5ee201e8cf2844b7500846f78c4"
            },
            "filename": "lib-streak-math-1.0.0.tgz"
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/lib-streak-math/MAL-2026-11141.json"
cwes 
[
    {
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature.",
        "name": "Embedded Malicious Code"
    }
]