Which versions of fulcrum-sessions are malicious?

The following npm versions of fulcrum-sessions are flagged malicious: 1.0.1, 1.1.0. Treat any of these as compromised.

How do I remediate fulcrum-sessions if I installed it?

fulcrum-sessions 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 fulcrum-sessions — how do I know if it already compromised me?

If fulcrum-sessions 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 fulcrum-sessions part of a known attack campaign?

Yes — fulcrum-sessions is associated with the IN-MAL-2026-003464, IN-MAL-2026-003460 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 fulcrum-sessions 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 fulcrum-sessions (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging fulcrum-sessions across your stack and pipelines.

Malicious package

fulcrum-sessionsnpm

Malicious code in fulcrum-sessions (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-4568

Immediate action

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

npm uninstall fulcrum-sessions

What this malware does

src/config.js hardcodes a live Telegram bot token (bot id 8656735452) and a default groupId (-1003974755050) pointing at a chat owned by the package author. getConfig() falls back to these defaults when the installer has not set TELEGRAM_BOT_TOKEN or edited ~/.fulcrum-sessions/config.json. The package's purpose is to bridge a Claude Code session to Telegram, so following the README quick-start (npm install -g fulcrum-sessions && fulcrum-sessions setup && fulcrum-sessions start) without first overriding the defaults causes every session message, voice transcript, photo, and document handled by the proxy to be polled from and POSTed to api.telegram.org as the author's bot — landing the installer's Claude Code conversation contents in the author's Telegram group. Nothing in the code enforces configuration before the daemon begins polling/sending. Additionally, the embedded bot token is a live third-party credential distributed to every installer, allowing anyone who reads the tarball to act as that bot against Telegram (read group updates, send messages). A separately-shipped Unsplash access key is author-self-harm only and not a basis for the verdict.

Malicious versions

2 flagged

1.0.11.1.0

Indicators of compromise (SHA-256)

ac82cf36a305545f8a74253f02cf75a7916409575e42abf67ba42d8ef1f26c58

f3971399e0fb1bd6c61f5306557512ed22dc0605747526b600b08626a50eb31e

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 fulcrum-sessions (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging fulcrum-sessions across your stack and pipelines.
If you installed it — respond
fulcrum-sessions 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 fulcrum-sessions 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 fulcrum-sessions 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. fulcrum-sessions on npm has been identified as a malicious package (versions 1.0.1, 1.1.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-003464IN-MAL-2026-003460

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks fulcrum-sessions-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