insomnia-plugin-poc-m4gesternpm
Malicious code in insomnia-plugin-poc-m4gester (npm) Remove it immediately and rotate any exposed credentials.
What this malware does
package.json declares a postinstall lifecycle hook that runs a shell command writing a marker file to /tmp on npm install ("postinstall": "echo PWNED_BY_DEEPLINK > /tmp/..."). The package ships no library code, no plugin implementation, and the description field is literally "test" — there is no advertised functionality to justify the install-time shell execution. The package name insomnia-plugin-poc-m4gester further self-identifies as a proof-of-concept exploit targeting the Insomnia REST client plugin namespace. Installing this package results in attacker-chosen shell execution on the installer's machine; the current payload is benign (a marker file write) but the mechanism is arbitrary code execution at install time and could trivially be swapped for a destructive or exfiltrating command in a future version.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for insomnia-plugin-poc-m4gester (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging insomnia-plugin-poc-m4gester across your stack and pipelines.
If you installed it — respond
insomnia-plugin-poc-m4gester is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If insomnia-plugin-poc-m4gester 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 insomnia-plugin-poc-m4gester 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 insomnia-plugin-poc-m4gester-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.