MAL-2026-17239

    Dashboard / Malicious Package / MAL-2026-17239

    MAL-2026-17239

    Published: 28 Sept 2026Last Modified: 28 Sept 2026

    Summary: Malicious code in test-agency-assignment (npm)

    Details: Source: amazon-inspector (dcdf62e1c1eb44ca7a29ed37c12bdb71883025a46c5066e58c9228f0dfe782c2) package.json declares a postinstall lifecycle script `wscript.exe 4444.vbs`, causing the VBS file shipped in the tarball to run automatically on `npm install` on Windows hosts. 4444.vbs contains a hand-rolled multi-layer decoder (Base64, an XOR-masked AES S-box, ChaCha20-IETF, additional XOR) that concatenates hundreds of embedded ~2KiB Base64 chunks stored in `ArtifactBundleHX(...)`, decrypts them, writes the resulting PowerShell loader to a randomly named file under %TEMP% (`pf<rand>.dat`), and invokes powershell.exe against it. In-file comments describe the handoff to PowerShell as being for process hollowing. The file header presents a benign 'Device Telemetry Aggregator' cover story that does not match the shipped behavior. The package's only functional content is this dropper; installing the package on Windows results in arbitrary attacker-controlled code execution on the installer's host.

    References: https://www.npmjs.com/package/test-agency-assignment/v/1.0.2

    Affected packages

    Package

    Name: test-agency-assignment

    Purl: pkg:npm/test-agency-assignment

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    1.0.2