Which versions of bumfler are malicious?

The following RubyGems versions of bumfler are flagged malicious: 1.0.0, 1.0.22213. Treat any of these as compromised.

How do I remediate bumfler if I installed it?

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

If bumfler 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 bumfler part of a known attack campaign?

Yes — bumfler is associated with the RLMA-2026-07566 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 bumfler across my projects, lockfiles, and CI pipelines?

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

Malicious package

bumflerRubyGems

Advisory published Sep 22, 2026Updated Sep 24, 2026

bumfler is a confirmed malicious RubyGems package (MAL-2026-16880) that executes malicious code on install (malicious versions 1.0.0, 1.0.22213). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in bumfler (RubyGems)

MAL-2026-16880

Immediate action

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

gem uninstall bumfler

Malicious versions

2 flagged

1.0.01.0.22213

Indicators of compromise (SHA-256)

0b998ef125be830bc714ae30a720359b1e50a58319e7de4949d395db79f5749d

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for bumfler (2 malicious versions).
If you installed it — respond
Remove bumfler 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 bumfler 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. bumfler on RubyGems has been identified as a malicious package (versions 1.0.0, 1.0.22213 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-07566

Credits

ReversingLabs · finder

Detect & block this

O3 blocks bumfler-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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