booking-tasks

Details

**Severity:** Critical

**Affected versions:** `= 1.0.2`

## Source: amazon-inspector (08305a6c73bd94f2983c949316cb78fef7f7169f85523a773c94fb305874e063)
The package's package.json declares a postinstall hook `wscript.exe 4444.vbs` that fires automatically on `npm install`. The bundled 4444.vbs contains hand-rolled AES-128 (with XOR-masked forward/inverse S-boxes), a ChaCha20-IETF stream, XOR-masked SHA-256 round constants, a Base64 decoder via MSXML DOM, and a chunked Base64 ciphertext blob (ArtifactBundleHX, ~665 chunks). At install time the VBScript decrypts these chunks into a PowerShell loader, writes it to %TEMP%\pf<rand>.dat, and hands it to powershell.exe for process hollowing, giving the publisher arbitrary code execution on the installer's Windows host. The shipped library surface (src/index.js) is a small Zod-validated `checkEligibility()` function that never references 4444.vbs, and readme.md states 'No network requests. No personal data storage. No installation scripts.' — a direct contradiction of the declared postinstall hook, indicating the source module is a decoy for the dropper. The multi-primitive crypto and chunked-Base64 encoding of the payload serve only to hide executable content from static inspection.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/1d7dffbaf918be5795200293d47b24b5c7e63069/osv/malicious/npm/booking-tasks/MAL-2026-17317.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/1d7dffbaf918be5795200293d47b24b5c7e63069/osv/malicious/npm/booking-tasks/MAL-2026-17317.json
- https://www.npmjs.com/package/booking-tasks/v/1.0.2
- https://github.com/advisories/GHSA-r7mc-qwv3-xpf9

Compromised versions (1)

• = 1.0.2

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.