catwrestlinghumannpm
Advisory published Updated
catwrestlinghuman is a confirmed malicious npm package (MAL-2026-16328) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in catwrestlinghuman (npm)
What this malware does
package.json declares a postinstall hook node index.js. index.js is a 111KB blob composed exclusively of the JSFuck character set ([]()!+), which decodes at runtime via Function(<decoded string>)() to arbitrary JavaScript. A sibling file extension.js (126KB) uses the same JSFuck encoding, indicating a multi-stage opaque payload. The package has no description, no author, and no dependencies, and ships no readable source — the JSFuck encoding is exclusively an obfuscation technique used to hide executable code from scanners and reviewers. Installing this package causes automatic execution of the opaque payload on the installer's machine during npm install.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for catwrestlinghuman (version 1.0.0).
If you installed it — respond
Remove catwrestlinghuman 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 catwrestlinghuman 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 catwrestlinghuman-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.