Which versions of bumcler are malicious?

The following RubyGems versions of bumcler are flagged malicious: 1.0.0, 1.0.13154. Treat any of these as compromised.

How do I remediate bumcler if I installed it?

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

If bumcler 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 bumcler part of a known attack campaign?

Yes — bumcler is associated with the RLMA-2026-07500 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 bumcler across my projects, lockfiles, and CI pipelines?

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

Malicious package

bumclerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumcler is a confirmed malicious RubyGems package (MAL-2026-16814) that executes malicious code on install (malicious versions 1.0.0, 1.0.13154). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumcler (RubyGems)

MAL-2026-16814

Immediate action

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

gem uninstall bumcler

Malicious versions

2 flagged

1.0.01.0.13154

Indicators of compromise (SHA-256)

e904155d13f9251f179524926486c09f46539d5bc5f0b9acb8f419b86f0288d9

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumcler (2 malicious versions).
If you installed it — respond
Remove bumcler 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 bumcler 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. bumcler on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.13154 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07500

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumcler-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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