Which versions of zyleys are malicious?

The following npm versions of zyleys are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate zyleys if I installed it?

Remove zyleys 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 zyleys — how do I know if it already compromised me?

If zyleys 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 zyleys across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for zyleys (version 1.0.0).

Malicious package

zyleysnpm

Advisory published Oct 27, 2026Updated Nov 9, 2026

zyleys is a confirmed malicious npm package (MAL-2026-19050) 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 zyleys (npm)

MAL-2026-19050

Immediate action

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

npm uninstall zyleys

What this malware does

zyleys 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) 120363367153552860@newsletter, 120363368585140499@newsletter, 120363422814525873@newsletter, 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 zyleys (version 1.0.0).
If you installed it — respond
Remove zyleys 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 zyleys 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. zyleys 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 zyleys-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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