kalipto-runtimenpm
Advisory published Updated
kalipto-runtime is a confirmed malicious npm package (MAL-2026-11087) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in kalipto-runtime (npm)
What this malware does
The package's main entry (src/server.js) is a self-executing Express server that binds to 0.0.0.0 on port 3000 and exposes POST /execute, which passes the request body's command field directly to child_process.exec with a 30-second timeout. The endpoint is gated by an API key read from process.env.RUNTIME_API_KEY, but the package's tarball includes a.env file containing RUNTIME_API_KEY=kalipto_runtime_secret_123 — a shared secret known to anyone who downloads the package from npm. Because main points at this server, both npm start and require('kalipto-runtime') cause the listener to come up. Any installer who runs this package exposes an internet-reachable arbitrary-command-execution service to every network their host is attached to, authenticated by a publicly known key. This is a backdoor: any attacker with the package contents (i.e., anyone) can run arbitrary shell commands on any host running the package.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for kalipto-runtime (version 1.0.0).
If you installed it — respond
kalipto-runtime establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If kalipto-runtime 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 kalipto-runtime-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.