Which versions of swcalcelf are malicious?

The following RubyGems versions of swcalcelf are flagged malicious: 0.0.1. Treat any of these as compromised.

How do I remediate swcalcelf if I installed it?

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

If swcalcelf 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 swcalcelf part of a known attack campaign?

Yes — swcalcelf is associated with the RLMA-2026-03578, RLUA-2026-09491 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 swcalcelf across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for swcalcelf (version 0.0.1).

Malicious package

swcalcelfRubyGems

Advisory published Jul 7, 2026Updated Sep 24, 2026

swcalcelf is a confirmed malicious RubyGems package (MAL-2026-8927) that executes malicious code on install (malicious version 0.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in swcalcelf (RubyGems)

MAL-2026-8927

Immediate action

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

gem uninstall swcalcelf

Malicious versions

1 flagged

0.0.1

Indicators of compromise (SHA-256)

51379af5ca68df6080e635ee61b20e3e01c23661b74cd1d1f2f694e20d60c572

77952b13e990270bba17d9b3cc497d6f64c3ecdfd0ca36a9d165548a9c3985ca

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for swcalcelf (version 0.0.1).
If you installed it — respond
Remove swcalcelf 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 swcalcelf 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. swcalcelf on RubyGems has been identified as a malicious package (version 0.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2026-03578RLUA-2026-09491

References

github.com

Credits

ReversingLabs · finder

Detect & block this

O3 blocks swcalcelf-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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