MAL-2026-14166

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Import Source
https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chalk-es/MAL-2026-14166.json
JSON Data
https://api.osv.dev/v1/vulns/MAL-2026-14166
Published
2026-08-18T23:58:23Z
Modified
2026-08-19T00:30:17.952495542Z
Summary
Malicious code in chalk-es (npm)
Details

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

Source: amazon-inspector (9a278b0c90f55a6a518b61ec1c964468011d1e4be184df5f36336a5f82ea58cc)

Package name mimics chalk but ships an empty library body; the only real behavior lives in scripts/postinstall.js. On install the script XOR-decodes (key stf2026) a hardcoded GitHub URL and downloads a Windows binary to %TEMP%\main.exe, then spawns it detached. On WSL/Linux hosts an XOR-decoded bridge command is exec'd to reach the underlying Windows host and run the same payload from inside Linux. The postinstall also POSTs a JSON body containing the resolved platform label (with WSL detection) to a hardcoded bare-IP endpoint at http://193.70.34.101:20099/vote, serving as an install beacon/victim tracker. Four byte-array constants (ADDONENC, BRIDGELAUNCHERENC, BRIDGESCRIPTPREENC, BRIDGESCRIPTPOST_ENC) are XOR-decoded at runtime specifically to hide the fetch URL and the Windows/WSL execution command.

Database specific 
{
    "malicious-packages-origins": [
        {
            "import_time": "2026-08-19T00:21:12.488453002Z",
            "sha256": "9a278b0c90f55a6a518b61ec1c964468011d1e4be184df5f36336a5f82ea58cc",
            "modified_time": "2026-08-18T23:58:23Z",
            "source": "amazon-inspector",
            "id": "IN-MAL-2026-018244",
            "versions": [
                "1.0.0"
            ]
        }
    ]
}
References
Credits

Affected packages

npm / chalk-es

Package

Name
chalk-es
View open source insights on deps.dev
Purl
pkg:npm/chalk-es

Affected ranges

Affected versions

1.*
1.0.0

Database specific

source 
"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/chalk-es/MAL-2026-14166.json"
indicators 
{
    "evidence_files": [
        {
            "sha256": "9c81289ea095aa745f5d06b9533c9f28df4b746dc445cec227f99dbeb1b2672e",
            "path": "scripts/postinstall.js",
            "tlsh": "00d13fca1ef59035874bf96884cf9d13b2a6c207320e4a65ff8f42107f5793c85a69e9"
        }
    ],
    "package_integrity": [
        {
            "filename": "chalk-es-1.0.0.tgz",
            "hashes": {
                "sha512_sri": "sha512-4HxTJMpaTcz7IVHO/obBwv+K8vi+ZuBdG3eTfN5fczEh1P2UpxWJ9mXtbLEUNvGOoqrTCydwTqH1dcRrdDNDTw==",
                "sha1": "454686356eaa6384547c7af31d3cf2ef967a23b4"
            }
        }
    ]
}
cwes 
[
    {
        "name": "Embedded Malicious Code",
        "cweId": "CWE-506",
        "description": "The product contains code that appears to be malicious in nature."
    }
]