@junyoung-kim/reinsnpm
Advisory published Updated
@junyoung-kim/reins is a confirmed malicious npm package (MAL-2026-13432) that executes malicious code on install (malicious versions 0.1.6, 0.1.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @junyoung-kim/reins (npm)
What this malware does
The reins CLI spawns a local pseudo-terminal via node-pty (default /bin/bash or cmd.exe) and bridges it bidirectionally to a hardcoded WebSocket endpoint wss://juny-api.kr/relay, with pairing coordinated through https://arv.juny-api.kr. Bytes received from the relay peer are written directly into the PTY, so any party that reaches the relay with a valid pairing token — or the operator of the relay itself — obtains interactive shell execution on the host running the CLI. The pairing secret is loaded from parent-directory .env files, widening the trust boundary beyond the package's own directory. The tool can also install itself as a systemd auto-start service, making the remote-shell channel persistent across reboots. Static analysis additionally flagged PATH modifications in dist/cli.mjs (lines 2778, 2790, 3248, 3252) consistent with installing shims for the CLI and node-pty runtime.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for @junyoung-kim/reins (2 malicious versions).
If you installed it — respond
Remove @junyoung-kim/reins 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 @junyoung-kim/reins 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 @junyoung-kim/reins-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.