MAL-2026-11766 Malicious code in @ornikar/prettier-config (npm)

npm/@ornikar/prettier-config is affected by the large-scale, self-propagating npm supply-chain worm of 2026-08-04 (the "Shai-Hulud: Here We Go Again" wave) — the same campaign that began with the compromise of the keyv and cacheable maintainer account. The listed version(s) were trojanized and republished by the worm after it reached an npm publish token belonging to a maintainer in this namespace; the payload enumerates every package a stolen token controls and republishes each with the same hook, so many packages under this scope were poisoned in the same short window. Every poisoned release adds a preinstall hook ("preinstall": "node setup.mjs") that runs on a bare npm install, before any project code. setup.mjs downloads a standalone Bun runtime and runs a byte-identical, heavily obfuscated ~728 KB second-stage credential stealer (shipped as Math_Symbol.js / math_init.js). It harvests GitHub, npm, AWS, GCP, Azure, HashiCorp Vault and Kubernetes credentials plus generic secrets and private keys (TruffleHog-style sweep), reads CI/CD secrets and identifies build runners, then republishes further packages the stolen token can reach. Rather than a fixed command-and-control host, it exfiltrates stolen findings to attacker-created GitHub repositories (descriptions reading "Shai-Hulud: Here We Go Again") and over DNS. Treat any environment that installed an affected version (with install scripts enabled) as compromised: rotate and revoke all reachable credentials (npm and GitHub tokens, cloud keys, Vault/Kubernetes secrets, and CI org/repo secrets). Part of the August 2026 npm worm that poisoned 400+ packages across many organizations.

This version of @ornikar/prettier-config declares a preinstall hook node setup.mjs that fires automatically on npm install. setup.mjs downloads the Bun runtime from github.com/oven-sh/bun releases (arch-specific zip), extracts it to a temp directory, chmods it executable, and invokes it via execFileSync to run a bundled sibling file math_init.js. math_init.js is a ~727KB single-line obfuscator.io-style payload (shuffled string array with a rotating shift routine, hex-mangled identifiers, multi-thousand-entry encoded constants table) whose filename has no relationship to the package's stated purpose. A Prettier config package's declared functionality is delivered entirely by a ~20-line index.js exporting a config object; there is no legitimate reason to fetch a second language runtime and execute an obfuscated blob under it at install time. The alternate-runtime execution path bypasses tooling that only inspects Node-resolved code. Prior legitimate versions of this package under the same @ornikar scope ship only the config file and declare no install hooks, so 9.0.6 introduces both the preinstall hook and the two undeclared payload files (setup.mjs, math_init.js).

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.