test-pkg-yarn
This report shows the evidence for test-pkg-yarn@1.0.2. 3 of 4 known versions are blocked or flagged. The newest version, 0.0.1-security, is allowed. See all versions.
OpenSSF/OSV Malicious Advisory
imported 4mo ago · by OpenSSF/OSVOpenSSF/OSV advisory MAL-2026-6718 confirms this npm version as malicious.
Advisory
MAL-2026-6718
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in test-pkg-yarn (npm)
Details
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 & flagged code
0 flagged · loading sourceNo flagged code excerpts are attached to this scan.
Findings
1 High
HighOsv Malicious Advisory
Affected versions and remediation
This report applies to test-pkg-yarn@1.0.2.
The same advisory and Firewall decision cover 3 recorded versions
1.0.0, 1.0.1, 1.0.2
The versions list below shows the verdict for each recorded version.
- Avoid installing test-pkg-yarn@1.0.2. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
This report uses published external intelligence. The advisory does not provide a separate source-code analysis for each listed version.
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