Which versions of bumdlser are malicious?

The following RubyGems versions of bumdlser are flagged malicious: 1.0.0, 1.0.45583. Treat any of these as compromised.

How do I remediate bumdlser if I installed it?

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

If bumdlser 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 bumdlser part of a known attack campaign?

Yes — bumdlser is associated with the RLMA-2026-07553 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 bumdlser across my projects, lockfiles, and CI pipelines?

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

Malicious package

bumdlserRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumdlser is a confirmed malicious RubyGems package (MAL-2026-16867) that executes malicious code on install (malicious versions 1.0.0, 1.0.45583). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumdlser (RubyGems)

MAL-2026-16867

Immediate action

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

gem uninstall bumdlser

Malicious versions

2 flagged

1.0.01.0.45583

Indicators of compromise (SHA-256)

f6376c910b43ceb2c7b445081816c33338b3d9513c94fd5f71e8a5ddb5c7a90f

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumdlser (2 malicious versions).
If you installed it — respond
Remove bumdlser 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 bumdlser 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. bumdlser on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.45583 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07553

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumdlser-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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