MAL-2026-6718
Malicious code in test-pkg-yarn (npm)
Details
--- _-= Per source details. Do not edit below this line.=-_
## Source: amazon-inspector (40b74339843ee482f3f135dd43e855f1f30758e20857333e0e6153748888769a) package.json declares `bin: { "node": "./shim.js" }`, causing `npm`/`yarn` to symlink `node` in `node_modules/.bin` (and in a system bin dir on global install) to a package-controlled script. Subsequent invocations of `node` resolved through that PATH entry execute shim.js instead of the real Node.js runtime, redirecting any tooling that expects `node` to attacker-controlled code. In addition, `scripts.postinstall` runs `bun shim.js || node shim.js`, and shim.js unconditionally invokes OS commands at install time via `child_process.execSync` — spawning a GUI calculator (`calc` on Windows, `gnome-calculator` on Linux, `open -a Calculator` on macOS), opening a URL in the user's browser, and writing a marker file to `/tmp/.bun-npm-pwned`. The package self-identifies as 'BunnyHijack PoC - yarn variant' with the console message '[!] PATH POISONED - test-pkg-yarn just hijacked your node command.' Although framed as a proof-of-concept and not currently exfiltrating data, the behavior is real install-time code execution against any developer who installs the package and a persistent hijack of the `node` command in PATH.
## Source: ghsa-malware (48a8aeea873fbdd85454d98cc80645d57e3f34365a075242704bbffd2ccb8c21) 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.
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Affected packages
0 No fixed version published yet for test-pkg-yarn (npm). Pin to a known-safe version or switch to an alternative.