Which versions of arc-cli-fc are malicious?

The following npm versions of arc-cli-fc are flagged malicious: 1.0.1. Treat any of these as compromised.

How do I remediate arc-cli-fc if I installed it?

arc-cli-fc is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed arc-cli-fc — how do I know if it already compromised me?

If arc-cli-fc 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.

Is arc-cli-fc part of a known attack campaign?

Yes — arc-cli-fc is associated with the GHSA-m788-q6w4-jjpr campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find arc-cli-fc across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for arc-cli-fc (version 1.0.1).

Malicious package

arc-cli-fcnpm

Advisory published Nov 24, 2025Updated Dec 1, 2025

arc-cli-fc is a confirmed malicious npm package (MAL-2025-191064) that steals credentials and exfiltrates sensitive data (malicious version 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in arc-cli-fc (npm)

MAL-2025-191064

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall arc-cli-fc

What this malware does

The package arc-cli-fc was found to contain malicious code.

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.

This package was compromised by the Sha1-Hulud: The Second Coming NPM worm. The malicious payload steals tokens and credentials and publishes them to GitHub. The worm will propogate itself to NPM packages the user owns and establish persistence is a GitHub action. The package may also destroy the user's home directory.

Malicious versions

1 flagged

1.0.1

Indicators of compromise (SHA-256)

2b66690547df94d6cac227e7ed304d7408b2344131612b96fd60575122bf7cbe

994c774c059e85133ba2ce3180ada5afad2b217667d6f611db0fcfe3482bef13

b6214b07e01a7c332d90dc0c32f225b76b8a3a8733256c42038ba1a6494a1794

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for arc-cli-fc (version 1.0.1).
If you installed it — respond
arc-cli-fc is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If arc-cli-fc 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

No. arc-cli-fc on npm has been identified as a malicious package (version 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GHSA-m788-q6w4-jjpr

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks arc-cli-fc-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database