MAL-2026-11646 Malicious code in @onereach/si-switch (npm)

npm/@onereach/si-switch 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.

@onereach/si-switch is published as a Vue UI component but ships a preinstall hook that runs setup.mjs, an obfuscator.io-mangled script. setup.mjs detects platform, architecture, and musl/Alpine, downloads a Bun runtime zip from github.com/oven-sh/bun/releases into an OS tmpdir, extracts it, chmods the binary, and execFileSyncs it against a sibling file math_init.js. math_init.js is a 727KB // @bun @bun-cjs bundle transformed with obfuscator.io (numeric/string constant array, rotator, and char-code decoder), so its network destinations, filesystem paths, and API calls are not statically recoverable. math_init.js is not listed in package.json files (which declares only lib/*), so the payload is smuggled into the tarball outside the declared publish surface. A Vue component has no legitimate need to fetch a separate language runtime and execute an opaque bundle under it at install time; the alternate-runtime execution path also bypasses Node-based static and runtime scanners.

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.