insomnia-plugin-poc-m4gester2npm
Advisory published Updated
insomnia-plugin-poc-m4gester2 is a confirmed malicious npm package (MAL-2026-6553) that executes malicious code on install (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in insomnia-plugin-poc-m4gester2 (npm)
What this malware does
Package ships only a package.json with no plugin code, declaring a postinstall lifecycle script that runs echo PWNED_BY_DEEPLINK > /tmp/pwned.txt on every npm install. This writes a marker file to the installer's filesystem and demonstrates arbitrary command execution at install time. The package name self-identifies as a proof-of-concept (poc-m4gester) and adopts the insomnia-plugin-* namespace despite shipping no Insomnia plugin functionality. While the current payload is a benign marker write, the postinstall is an arbitrary-shell-on-install primitive with no legitimate purpose, in a namespace-squat shell of a package.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for insomnia-plugin-poc-m4gester2 (2 malicious versions).
If you installed it — respond
Remove insomnia-plugin-poc-m4gester2 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 insomnia-plugin-poc-m4gester2 was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks insomnia-plugin-poc-m4gester2-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.