Which versions of zwan_cal_jan1 are malicious?

The following RubyGems versions of zwan_cal_jan1 are flagged malicious: 0.0.131. Treat any of these as compromised.

How do I remediate zwan_cal_jan1 if I installed it?

Remove zwan_cal_jan1 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 zwan_cal_jan1 — how do I know if it already compromised me?

If zwan_cal_jan1 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 zwan_cal_jan1 part of a known attack campaign?

Yes — zwan_cal_jan1 is associated with the RLMA-2026-04488, RLUA-2026-10426 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 zwan_cal_jan1 across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for zwan_cal_jan1 (version 0.0.131).

Malicious package

zwan_cal_jan1RubyGems

Advisory published Jul 7, 2026Updated Sep 24, 2026

zwan_cal_jan1 is a confirmed malicious RubyGems package (MAL-2026-9837) that executes malicious code on install (malicious version 0.0.131). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in zwan_cal_jan1 (RubyGems)

MAL-2026-9837

Immediate action

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

gem uninstall zwan_cal_jan1

Malicious versions

1 flagged

0.0.131

Indicators of compromise (SHA-256)

5d13df4dd29eb0277390a1accb79dbcaa7195410d604cf519f6a2252102a0cc3

b3880bd4d4eb31a32fd9595882e148a549e9dcfb6c3a7c2968eede2e6ec30abf

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for zwan_cal_jan1 (version 0.0.131).
If you installed it — respond
Remove zwan_cal_jan1 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 zwan_cal_jan1 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. zwan_cal_jan1 on RubyGems has been identified as a malicious package (version 0.0.131 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-04488RLUA-2026-10426

References

Credits

ReversingLabs · finder

Detect & block this

O3 blocks zwan_cal_jan1-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