Which versions of chai-sync are malicious?

The following npm versions of chai-sync are flagged malicious: 1.1.9, 2.2.4, 2.2.6. Treat any of these as compromised.

How do I remediate chai-sync if I installed it?

Remove chai-sync 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 chai-sync — how do I know if it already compromised me?

If chai-sync 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.

Is chai-sync part of a known attack campaign?

Yes — chai-sync is associated with the RLMA-2025-05701, RLUA-2025-06093, RLUA-2026-01193, RLUA-2026-01728 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 chai-sync across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for chai-sync (3 malicious versions).

Malicious package

chai-syncnpm

Advisory published Dec 1, 2025Updated Apr 1, 2026

chai-sync is a confirmed malicious npm package (MAL-2025-191567) that executes malicious code on install (malicious versions 1.1.9, 2.2.4, 2.2.6). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in chai-sync (npm)

MAL-2025-191567

Immediate action

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

npm uninstall chai-sync

What this malware does

The package chai-sync was found to contain malicious code.

Malicious versions

3 flagged

1.1.92.2.42.2.6

Indicators of compromise (SHA-256)

dd2e623fc4ef1feee3582c3bba6c89f9923339cf86f383cef500439b31713a56

f58d95adcd5fd2dce29ac379c47d6b4ca7239ae5d1eb53d06617067cc7623938

ec1194f0b43e545cc35705383e2f3195132acdb7f0117f54a814eac3f7e446fa

e306fab58c6a3b7ea982a5c069d4799a198fc2d9a9ecb81b47e9ac7b4253596f

fa02c1dd84e38e3cf7de19ecd9c59205baebc39bd1c9aabf12c356cc3e336465

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for chai-sync (3 malicious versions).
If you installed it — respond
Remove chai-sync 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 chai-sync 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. chai-sync on npm has been identified as a malicious package (versions 1.1.9, 2.2.4, 2.2.6 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-05701RLUA-2025-06093RLUA-2026-01193RLUA-2026-01728

References

Credits

Amazon Inspector · finder
ReversingLabs · finder

Detect & block this

O3 blocks chai-sync-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

All malware advisories How O3 detects malware Vulnerability database