chai-as-testkit

GHSA-4wfj-hpq9-58mw

Malicious code in chai-as-testkit (npm)

Details

**Severity:** Critical

**Affected versions:** `= 2.3.5`

## Source: amazon-inspector (0bf8ab4a811449bd1ba40c637a0eebc0569994d3a3550cf7156c36192abcec31)
The package is published as 'chai-as-testkit' with a description referencing vulnerability management, but the tarball ships pino's README, docs/, index.d.ts, and lib/ tree (proto, levels, transport, worker, redaction) under an unrelated author (Robert King <[email protected]>, bugs.url jsonspack.com) rather than the real pinojs publisher. The shipped index.js is a synthetic stub whose only effect is `const config = require('./lib/config')`, and lib/config.js is a 4,083,409-byte single-line obfuscator.io-style bundle: a rotated hex-escaped string array of ~23,953 entries with control-flow flattening and dead-code layers (webcrack inlines 40,105 decoded strings across the decoder layers before failing to serialize). This blob runs immediately when any consumer imports the package, executing attacker-controlled code inside the developer or CI Node.js process. The pino impersonation is the social-engineering wrapper around an on-import loader; the shape (name/description/author mismatch + hollow main entry that delegates to a multi-megabyte obfuscated module at require time) is a typosquat-delivered install/import-time RCE vehicle rather than a logging library.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/51911d234a84078e05bdf54c4b86161625e68d64/osv/malicious/npm/chai-as-testkit/MAL-2026-14371.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/51911d234a84078e05bdf54c4b86161625e68d64/osv/malicious/npm/chai-as-testkit/MAL-2026-14371.json
- https://www.npmjs.com/package/chai-as-testkit/v/2.3.5
- https://github.com/ossf/malicious-packages/blob/4012598c9b06e58935bd8883f7a0cd37c3130664/osv/malicious/npm/chai-as-testkit/MAL-2026-14371.json
- https://github.com/advisories/GHSA-4wfj-hpq9-58mw

Compromised versions (1)

= 2.3.5

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