registry / pob-test-package-in-monorepo / 5.2.9

pob-test-package-in-monorepo@5.2.9

test pob

AI Security Review

scanned 11d ago · by lpm-firewall-ai

Installing the package triggers a downloader that executes an obfuscated payload. The payload fetches and evaluates remote content and contains token-related logic.

Static reason

One or more suspicious static signals were detected.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review

Trigger

npm install (preinstall)

Impact

Arbitrary install-time code execution and likely credential/token theft.

Mechanism

bootstrap Bun, execute obfuscated remote-code payload

Attack narrative

The preinstall hook runs setup.mjs. It uses an existing Bun binary or downloads one from GitHub, then executes math_init.js. That large obfuscated payload contains remote fetch plus eval and token/child-process handling, creating an install-time remote-code execution chain unrelated to the package's trivial exported API.

Rationale

Source inspection confirms a concrete, unconsented preinstall bootstrapper executing an obfuscated payload that evaluates remotely supplied code. This is malicious behavior, not a package-aligned installation need.

Evidence

package.jsonsetup.mjsmath_init.jslib/index.js

Network endpoints1

github.com

OSV Corroboration

OpenSSF/OSV

npm/pob-test-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. --- ## Source: amazon-inspector (6eb7ddc4a79c6308d6e2f29098479c1bc943a2a0e7d9eb753c649ba11f083d80) pob-test-package-in-monorepo@5.2.7 advertises a trivial library whose lib/index.js is six lines exporting the string 'John'. The tarball additionally ships setup.mjs and math_init.js, and package.json declares scripts.preinstall = 'node setup.mjs'. On npm install, setup.mjs downloads the Bun runtime binary from https://github.com/oven-sh/bun/releases/download/bun-v1.3.13/<arch>.zip into a temp directory, chmods it executable, and invokes execFileSync(bunPath, [math_init.js]). math_init.js is a ~727KB single-line Bun-CJS bundle (// @bun @bun-cjs header) with hex-named identifiers (_0xXXXX), a shuffled string array (n7gIxM), and a rotator/decoder pair (WV8StW, hc1jfK9) — obfuscator.io-style packing that executes under the freshly downloaded alien runtime, bypassing Node-based scanning of the shipped source. The CHANGELOG's most recent entry is 5.2.0 ('test feat2'); setup.mjs and math_init.js are not documented in any changelog entry, and are structurally unrelated to a package whose declared purpose is exporting one string literal. The alternate-runtime dropper shape, the mismatch between declared purpose and shipped contents, and the undocumented addition of a large obfuscated payload in a point release are consistent with an unauthorized publish of a hijacked package name. ## Source: ghsa-malware (61528d410a4f483327b9b70a274c336e2920ac7fcc40be2a7c76d8ac90a7cb27) 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.

pob-test-package-in-monorepo@5.2.9

AI Security Review

OSV Corroboration

Decision evidence

Source & flagged code

Source & flagged code

Findings

Source & flagged code