cache-poisoning-pwn-demonpm
Malicious code in cache-poisoning-pwn-demo (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
The package's postinstall hook (node -e "try { require('./dist/postinstall.js'); } catch(e) {}") loads dist/postinstall.js, which bundles a poisoned is-number module whose top-level IIFE unconditionally calls child_process.exec with a platform-specific command: open -a Calculator on macOS, calc.exe on Windows, gnome-calculator/xcalc on Linux. The same IIFE is also present in dist/index.js (the package's main entry), so any consumer that does require('cache-poisoning-pwn-demo') or imports it will also spawn a child process with no user consent. The package self-describes as a supply-chain attack demonstration. While today's payload spawns only a calculator, the mechanism is a fully functional install-time and import-time arbitrary-command executor: any installer running npm install or any downstream library that transitively requires this package will execute the hardcoded command in the installer's context. The calculator is a demonstration payload; the delivery primitive is a real attack.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for cache-poisoning-pwn-demo (3 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging cache-poisoning-pwn-demo across your stack and pipelines.
If you installed it — respond
Remove cache-poisoning-pwn-demo from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If cache-poisoning-pwn-demo was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks cache-poisoning-pwn-demo before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks cache-poisoning-pwn-demo-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.