Which versions of biundelr are malicious?

The following RubyGems versions of biundelr are flagged malicious: 1.0.0, 1.0.26209. Treat any of these as compromised.

How do I remediate biundelr if I installed it?

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

If biundelr 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 biundelr part of a known attack campaign?

Yes — biundelr is associated with the RLMA-2026-07297 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 biundelr across my projects, lockfiles, and CI pipelines?

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

Malicious package

biundelrRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

biundelr is a confirmed malicious RubyGems package (MAL-2026-16633) that executes malicious code on install (malicious versions 1.0.0, 1.0.26209). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in biundelr (RubyGems)

MAL-2026-16633

Immediate action

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

gem uninstall biundelr

Malicious versions

2 flagged

1.0.01.0.26209

Indicators of compromise (SHA-256)

5892af96676504fc578db73552beb3419e5e151dd66af0e7a20389bb9db618b1

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for biundelr (2 malicious versions).
If you installed it — respond
Remove biundelr 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 biundelr 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. biundelr on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.26209 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07297

Credits

ReversingLabs · finder

Detect & block this

O3 blocks biundelr-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