Which versions of @kurtucoben/cstm-bail are malicious?

The following npm versions of @kurtucoben/cstm-bail are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate @kurtucoben/cstm-bail if I installed it?

Remove @kurtucoben/cstm-bail 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.

I already installed @kurtucoben/cstm-bail — how do I know if it already compromised me?

If @kurtucoben/cstm-bail 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.

How do I find @kurtucoben/cstm-bail across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for @kurtucoben/cstm-bail (version 1.0.0).

Malicious package

@kurtucoben/cstm-bailnpm

Advisory published Oct 27, 2026Updated Nov 9, 2026

@kurtucoben/cstm-bail is a confirmed malicious npm package (MAL-2026-18857) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in @kurtucoben/cstm-bail (npm)

MAL-2026-18857

Immediate action

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

npm uninstall @kurtucoben/cstm-bail

What this malware does

@kurtucoben/cstm-bail is a fork of the Baileys WhatsApp Web library that silently subscribes the installer's own WhatsApp account to WhatsApp Channels chosen by the publisher. When the socket connects, code in lib/Socket/newsletter.js sends the WhatsApp w:mex FOLLOW query for the channel ID(s) 120363401967885236@newsletter (stored as base64 strings), using the victim's authenticated session and without telling them. Same behaviour as the PhantomSub family (MAL-2026-17342).

Malicious versions

1 flagged

1.0.0

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for @kurtucoben/cstm-bail (version 1.0.0).
If you installed it — respond
Remove @kurtucoben/cstm-bail 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 @kurtucoben/cstm-bail 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. @kurtucoben/cstm-bail on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

References

Credits

CyberXYZ · finder

Detect & block this

O3 blocks @kurtucoben/cstm-bail-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.

Malware detection Runtime egress monitoring

Explore

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