Which versions of c00_arcguide are malicious?

The following RubyGems versions of c00_arcguide are flagged malicious: 0.0.1. Treat any of these as compromised.

How do I remediate c00_arcguide if I installed it?

Remove c00_arcguide 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 c00_arcguide — how do I know if it already compromised me?

If c00_arcguide 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 c00_arcguide part of a known attack campaign?

Yes — c00_arcguide is associated with the RLMA-2026-02205 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 c00_arcguide across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for c00_arcguide (version 0.0.1).

Malicious package

c00_arcguideRubyGems

Advisory published Jul 7, 2026Updated Jul 23, 2026

c00_arcguide is a confirmed malicious RubyGems package (MAL-2026-7554) that executes malicious code on install (malicious version 0.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in c00_arcguide (RubyGems)

MAL-2026-7554

Immediate action

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

gem uninstall c00_arcguide

Malicious versions

1 flagged

0.0.1

Indicators of compromise (SHA-256)

3f2a6c23eb77c569cba1f96de8b1502087f7aa691f92a3ee0d6645df3174f451

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for c00_arcguide (version 0.0.1).
If you installed it — respond
Remove c00_arcguide 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 c00_arcguide 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. c00_arcguide on RubyGems has been identified as a malicious package (version 0.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-02205

Credits

ReversingLabs · finder

Detect & block this

O3 blocks c00_arcguide-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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