Which versions of critter are malicious?

The following RubyGems versions of critter are flagged malicious: 90002.0. Treat any of these as compromised.

How do I remediate critter if I installed it?

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

If critter 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 critter part of a known attack campaign?

Yes — critter is associated with the RLMA-2025-06612, RLUA-2026-07946 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 critter across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for critter (version 90002.0).

Malicious package

critterRubyGems

Advisory published Dec 23, 2025Updated Sep 24, 2026

critter is a confirmed malicious RubyGems package (MAL-2025-192905) that executes malicious code on install (malicious version 90002.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in critter (RubyGems)

MAL-2025-192905

Immediate action

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

gem uninstall critter

Malicious versions

1 flagged

90002.0

Indicators of compromise (SHA-256)

2cb52d270b635577fc4c9a01ef5278a85f527bc6a8d91f1562db41d32d817880

ffe9f255a2fe69fb498962bffd9be90ef7583e77bcb1b5ce39706935be5c855d

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for critter (version 90002.0).
If you installed it — respond
Remove critter 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 critter 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. critter on RubyGems has been identified as a malicious package (version 90002.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-06612RLUA-2026-07946

References

github.com

Credits

ReversingLabs · finder

Detect & block this

O3 blocks critter-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

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