pob-test-typescript-package-in-monoreponpm

npm/pob-test-typescript-package-in-monorepo 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's preinstall lifecycle script (node setup.mjs) checks for a local bun binary and, if absent, downloads the Bun runtime from GitHub releases, extracts it to a temporary directory, marks it executable, and uses it to execute a bundled math_init.js file via execFileSync. The invoked math_init.js is a single-line ~727 KB script using obfuscator.io-style string-array plus array-shuffle indirection (large numeric/character array, a rotator function, hex-named identifiers) so that URLs and behaviors are reconstructed only at runtime and are not statically resolvable. The alien-runtime hop causes the payload to be executed outside Node's module graph, bypassing tools that trace only Node-resolved code. The package name presents as a test/monorepo scaffold, which does not match shipping and executing a large obfuscated blob via a freshly-downloaded second language runtime at install time. This is the alternate-runtime dropper shape: install-time execution of an opaque payload delivered through a runtime the package itself pulls in.

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.