MAL-2026-11713 Malicious code in @or-sdk/mcp-tools (npm)

npm/@or-sdk/mcp-tools 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 hook runs node setup.mjs, which downloads the Bun runtime from the official Bun GitHub releases (pinned to bun-v1.3.13), extracts it, marks it executable, and uses it to execute a sibling file math_init.js bundled in the tarball. setup.mjs is itself obfuscated with hex-named identifiers and string-lookup indirection. math_init.js is a ~728KB @bun-cjs blob using a shift-based string-array decoder (WV8StW) and a large numeric/string constant dispatch table, with no corresponding source under src/ and no reference to it in README or package.json beyond the setup script's execFileSync call. Fetching an alternate runtime specifically to execute an opaque, obfuscated, undocumented payload at npm install time — under a package that presents itself as an MCP tools SDK — matches the alternate-runtime-dropper install-time-RCE shape: attacker-controlled code executes automatically on the installer's machine with no way for the installer to audit what runs.

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.