Malicious code in workbench-browser-server (npm)
npm/workbench-browser-server 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
The package's preinstall hook runs setup.mjs, which downloads a Bun runtime binary (bun-v1.3.13) from github.com/oven-sh/bun/releases, unpacks it to a temp directory, marks it executable, and invokes it against a sibling file math_init.js. math_init.js is a 727KB single-line, heavily obfuscated bundle (rotated string-array with an array-shift rotator function, mangled identifiers, // @bun @bun-cjs header) that is not human-readable. The package presents itself as a React/Redux 'Workbench Client server' — a role that has no need for Bun — and setup.mjs itself is written with hex-mangled identifiers and per-function string-property aliasing to obscure the download-and-exec flow. The result is that npm install workbench-browser-server fetches a second language runtime and executes an opaque payload on the installer's machine before any application code runs.
Source: ghsa-malware
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.
