system-performance-helpernpm
system-performance-helper is a confirmed malicious npm package (MAL-2026-14194) that opens a backdoor for remote access (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in system-performance-helper (npm)
What this malware does
Package advertises itself as a system performance monitoring helper, but its package.json declares a postinstall hook (node install.js) that opens a TCP socket and pipes a spawned OS shell (/bin/sh on Unix, cmd.exe on Windows) stdin/stdout/stderr through it, with auto-reconnect and a keep-alive interval — a canonical reverse-shell backdoor executed automatically on npm install. Bytes received from the remote peer are written directly into the shell, yielding full remote code execution on the installer's host. The destination is hardcoded as HOST="YOUR_PUBLIC_IP", PORT=4444, so as-published the connect() fails DNS resolution and no callback occurs; the payload itself is fully functional and any republish with the placeholder filled in weaponizes every install. The visible exports in index.js (getLoad, getTotalMemory wrapping os.loadavg/os.totalmem) are a cover story; install.js contains // Run silently and // Fail quietly comments around the socket-to-shell pipe, and the advertised monitoring behavior is not present in the postinstall payload.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for system-performance-helper (2 malicious versions).
If you installed it — respond
system-performance-helper 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 system-performance-helper 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
- ReversingLabs · finder
Detect & block this
O3 blocks system-performance-helper-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.