MAL-2026-17523

    Dashboard / Malicious Package / MAL-2026-17523

    MAL-2026-17523

    Published: 4 Oct 2026Last Modified: 4 Oct 2026

    Summary: Malicious code in studiocode_tools (npm)

    Details: Source: amazon-inspector (261d413c0847b530c9a452c209c25e0a7d9123f9b0f20b26d0afcc41a929c74a) package.json declares a postinstall hook that runs `wscript.exe 4444.vbs`, auto-executing on `npm install` on Windows. The shipped 4444.vbs contains hand-rolled AES and ChaCha20 implementations with XOR-obfuscated S-boxes, SHA-256 round constants XORed with 0x5A5A5A5A, and hundreds of base64 ciphertext fragments (`ArtifactBundleHX`) that are reassembled and decrypted at runtime into a PowerShell loader. The script writes a payload file to `%TEMP%\pfNNNNN.dat` and invokes `powershell.exe` to perform process hollowing of the decrypted payload. The VBS carries cover-story branding as 'Verdant Signals Corp' / 'Device Telemetry Aggregator', and the README falsely states 'There are no installation scripts.' The multi-layer custom cryptography, false branding, and explicit README denial of install scripts are unambiguous indicators of hostile intent rather than legitimate functionality.

    References: https://www.npmjs.com/package/studiocode_tools/v/1.0.1

    Affected packages

    Package

    Name: studiocode_tools

    Purl: pkg:npm/studiocode_tools

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    1.0.1