MAL-2026-11748 Malicious code in @ornikar/eslint-config-formatjs (npm)

npm/@ornikar/eslint-config-formatjs 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.

The package declares itself as an ESLint formatjs configuration, but its preinstall lifecycle hook (node setup.mjs) downloads the Bun runtime v1.3.13 from github.com/oven-sh/bun/releases into a temporary directory, chmods it executable, and uses it to run a bundled 727KB single-line file math_init.js shipped in the tarball. math_init.js is heavily obfuscated (string-array/index rotator WV8StW, hex identifier table, // @bun @bun-cjs header) and has no relationship to ESLint or formatjs configuration. setup.mjs itself is obfuscator.io-mangled (hex identifiers like _0x488df8, dispatch objects { YCZJE, QkQej, JBhWy } wrapping trivial fs/https/execFileSync calls), hiding the fetch-and-execute chain from casual inspection. The combination — an ESLint config package fetching an alternate JavaScript runtime at install to execute a large opaque sibling payload, with both the lifecycle script and the payload obfuscated — is the alternate-runtime dropper pattern designed to bypass Node-based inspection. The fetched runtime is legitimate (Bun's official release), but it is being used as an execution vehicle for the shipped obfuscated payload, whose behavior cannot be inferred from source and which has no benign explanation for this package's declared purpose.

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.