Which versions of beundler are malicious?

The following RubyGems versions of beundler are flagged malicious: 1.0.0, 1.0.36258. Treat any of these as compromised.

How do I remediate beundler if I installed it?

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

If beundler 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 beundler part of a known attack campaign?

Yes — beundler is associated with the RLMA-2026-07243 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 beundler across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for beundler (2 malicious versions).

Malicious package

beundlerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

beundler is a confirmed malicious RubyGems package (MAL-2026-16585) that executes malicious code on install (malicious versions 1.0.0, 1.0.36258). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in beundler (RubyGems)

MAL-2026-16585

Immediate action

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

gem uninstall beundler

Malicious versions

2 flagged

1.0.01.0.36258

Indicators of compromise (SHA-256)

cfd174462ade326062d06de3f0ff1bee887f3c46e81e2fbfeb06867afeabf31a

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for beundler (2 malicious versions).
If you installed it — respond
Remove beundler 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 beundler 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. beundler on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.36258 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07243

Credits

ReversingLabs · finder

Detect & block this

O3 blocks beundler-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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