Which versions of activerecord-msgpack-serializer are malicious?

The following RubyGems versions of activerecord-msgpack-serializer are flagged malicious: 0.1.1. Treat any of these as compromised.

How do I remediate activerecord-msgpack-serializer if I installed it?

Remove activerecord-msgpack-serializer 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 activerecord-msgpack-serializer — how do I know if it already compromised me?

If activerecord-msgpack-serializer 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 activerecord-msgpack-serializer part of a known attack campaign?

Yes — activerecord-msgpack-serializer is associated with the RLMA-2024-05277, RLUA-2024-09796 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 activerecord-msgpack-serializer across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for activerecord-msgpack-serializer (version 0.1.1).

Malicious package

activerecord-msgpack-serializerRubyGems

activerecord-msgpack-serializer is a confirmed malicious RubyGems package (MAL-2024-6471) that executes malicious code on install (malicious version 0.1.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in activerecord-msgpack-serializer (RubyGems)

MAL-2024-6471

Immediate action

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

gem uninstall activerecord-msgpack-serializer

Malicious versions

1 flagged

0.1.1

Indicators of compromise (SHA-256)

1227bc124c369caf9527dcd8e2786fdc234023e31069884a13c84a77ca64f08a

476bbe1cb8e40c670bb39ad48af15cb562232b37d5582b0cc599930602d236bb

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for activerecord-msgpack-serializer (version 0.1.1).
If you installed it — respond
Remove activerecord-msgpack-serializer 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 activerecord-msgpack-serializer 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. activerecord-msgpack-serializer on RubyGems has been identified as a malicious package (version 0.1.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2024-05277RLUA-2024-09796

References

blog.reversinglabs.com

Credits

ReversingLabs · finder

Detect & block this

O3 blocks activerecord-msgpack-serializer-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