Which versions of bumdlerr are malicious?

The following RubyGems versions of bumdlerr are flagged malicious: 1.0.0, 1.0.98484. Treat any of these as compromised.

How do I remediate bumdlerr if I installed it?

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

If bumdlerr 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 bumdlerr part of a known attack campaign?

Yes — bumdlerr is associated with the RLMA-2026-07538 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 bumdlerr across my projects, lockfiles, and CI pipelines?

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

Malicious package

bumdlerrRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumdlerr is a confirmed malicious RubyGems package (MAL-2026-16852) that executes malicious code on install (malicious versions 1.0.0, 1.0.98484). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumdlerr (RubyGems)

MAL-2026-16852

Immediate action

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

gem uninstall bumdlerr

Malicious versions

2 flagged

1.0.01.0.98484

Indicators of compromise (SHA-256)

d2ce805e95c0543e6c5cf44df042604eb429f29b6511c12a211a59113a180127

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumdlerr (2 malicious versions).
If you installed it — respond
Remove bumdlerr 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 bumdlerr 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. bumdlerr on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.98484 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07538

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumdlerr-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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