MAL-2026-13356 Malicious code in chai-foundry (npm)

[email protected] is a trojan package presenting itself as a chai plugin (README shows chai.use(chaiLeaf)) while its badges, documentation, and internal version metadata (lib/meta.js exports version 9.6.0) are copied from the pino logger. The package's main entry index.js immediately loads ./lib/config, a 3.5MB file that is heavily obfuscated with obfuscator.io-class transforms: a rotated string array of 20,855 entries, two runtime decoder functions, tens of thousands of decoder-wrapper indirections, and control-flow flattening (104,934 deobfuscation changes reported by webcrack). The file begins with a top-level IIFE, so its opaque body runs automatically the moment any consumer calls require('chai-foundry'). All destinations and string constants are reconstructed at runtime, so the payload's network endpoints and behaviors are hidden from static inspection. The combination of identity impersonation, mismatched metadata, and a multi-megabyte control-flow-flattened import-time loader in a package advertised as a small chai plugin is the canonical shape of a hostile npm dropper/stealer.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.