MAL-2026-12501

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/william-data-formatter-x/MAL-2026-12501.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-12501
Published
2026-08-05T12:23:00Z
Modified
2026-08-05T13:36:27Z
Summary
Malicious code in william-data-formatter-x (npm)
Details

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

Source: amazon-inspector (df0b15d8ca8cdfac8baf861a2db501b3b52eb0e41fd44a6690c351bda8c90835)

The package declares a preinstall script (node index.js) that, on Windows, spawns a hidden PowerShell window (-WindowStyle Hidden) to fetch https://files.catbox.moe/5khq55.zip, extract it to %TEMP%, and execute Verification_Tool.exe. The fetched binary is unpinned, unhashed, and hosted on an anonymous file-drop service unrelated to the package's stated purpose. The package name has a leading space (' william-data-formatter-x') and carries generic 'Internal sync utility' / 'IT Operations' metadata consistent with social-engineering framing. Installing this package on a Windows machine results in arbitrary attacker-controlled code executing on the installer's host at npm install time.

Database specific 
{
    "malicious-packages-origins":  [
        {
            "id":  "IN-MAL-2026-014637",
            "import_time":  "2026-08-05T13:08:32.612383756Z",
            "modified_time":  "2026-08-05T12:23:00Z",
            "sha256":  "df0b15d8ca8cdfac8baf861a2db501b3b52eb0e41fd44a6690c351bda8c90835",
            "source":  "amazon-inspector",
            "versions":  [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / william-data-formatter-x

Package

Name
william-data-formatter-x
View open source insights on deps.dev
Purl
pkg:npm/william-data-formatter-x

Affected ranges

Affected versions

1.*
1.0.0

Database specific

cwes 
[
    {
        "cweId":  "CWE-506",
        "description":  "The product contains code that appears to be malicious in nature.",
        "name":  "Embedded Malicious Code"
    }
]
indicators 
{
    "evidence_files":  [
        {
            "path":  "index.js",
            "sha256":  "d456c8e6d47b64505e530d5648071be4319c4abd35a0fa3ee07772111cab9152",
            "tlsh":  "66f0dcb243e99034db709ac3bb9137432853d71a1a13e25219aa41857f14a108bdb8ed"
        }
    ],
    "package_integrity":  [
        {
            "filename":  "william-data-formatter-x-1.0.0.tgz",
            "hashes":  {
                "sha1":  "226743ce2927e9bea3b7a660f7e6f3ffb64185d3",
                "sha512_sri":  "sha512-OXWF11tJsu7iPrwOQuvMFbd7cEEVYpVgRByW9iUgIVGIBbk9Ogij+ob7FgWBSG6Wxngb0IcsgiR5dUHSsv/CeA=="
            }
        }
    ]
}
source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/william-data-formatter-x/MAL-2026-12501.json"