Which versions of banlder are malicious?

The following RubyGems versions of banlder are flagged malicious: 1.0.0, 1.0.7412. Treat any of these as compromised.

How do I remediate banlder if I installed it?

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

If banlder 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 banlder part of a known attack campaign?

Yes — banlder is associated with the RLMA-2026-07191 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 banlder across my projects, lockfiles, and CI pipelines?

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

Malicious package

banlderRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

banlder is a confirmed malicious RubyGems package (MAL-2026-16564) that executes malicious code on install (malicious versions 1.0.0, 1.0.7412). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in banlder (RubyGems)

MAL-2026-16564

Immediate action

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

gem uninstall banlder

Malicious versions

2 flagged

1.0.01.0.7412

Indicators of compromise (SHA-256)

561d7af156b486f5f3cc4bef514693de41068dac4e398b7d7fada81acb611cbb

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for banlder (2 malicious versions).
If you installed it — respond
Remove banlder 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 banlder 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. banlder on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.7412 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07191

Credits

ReversingLabs · finder

Detect & block this

O3 blocks banlder-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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