Which versions of bumler are malicious?

The following RubyGems versions of bumler are flagged malicious: 1.0.0, 1.0.60219. Treat any of these as compromised.

How do I remediate bumler if I installed it?

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

If bumler 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 bumler part of a known attack campaign?

Yes — bumler is associated with the RLMA-2026-07571 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 bumler across my projects, lockfiles, and CI pipelines?

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

Malicious package

bumlerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumler is a confirmed malicious RubyGems package (MAL-2026-16885) that executes malicious code on install (malicious versions 1.0.0, 1.0.60219). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumler (RubyGems)

MAL-2026-16885

Immediate action

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

gem uninstall bumler

Malicious versions

2 flagged

1.0.01.0.60219

Indicators of compromise (SHA-256)

e5e6193b6840c6fc15ea238959955f421fd0af30e0221695d21ad150f57a2f8e

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumler (2 malicious versions).
If you installed it — respond
Remove bumler 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 bumler 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. bumler on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.60219 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07571

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumler-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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