Which versions of bnlder are malicious?

The following RubyGems versions of bnlder are flagged malicious: 1.0.0, 1.0.57005. Treat any of these as compromised.

How do I remediate bnlder if I installed it?

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

If bnlder 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 bnlder part of a known attack campaign?

Yes — bnlder is associated with the RLMA-2026-07401 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 bnlder across my projects, lockfiles, and CI pipelines?

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

Malicious package

bnlderRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bnlder is a confirmed malicious RubyGems package (MAL-2026-16733) that executes malicious code on install (malicious versions 1.0.0, 1.0.57005). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bnlder (RubyGems)

MAL-2026-16733

Immediate action

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

gem uninstall bnlder

Malicious versions

2 flagged

1.0.01.0.57005

Indicators of compromise (SHA-256)

244cfb1b4424d0c94280863f98ee07b9e2d47874691aaa7cdb9ce7eb8d24cf36

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bnlder (2 malicious versions).
If you installed it — respond
Remove bnlder 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 bnlder 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. bnlder on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.57005 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07401

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bnlder-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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