Which versions of dextester are malicious?

The following RubyGems versions of dextester are flagged malicious: 9.9.9. Treat any of these as compromised.

How do I remediate dextester if I installed it?

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

If dextester 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 dextester part of a known attack campaign?

Yes — dextester is associated with the RLMA-2025-00552, RLUA-2026-07976 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 dextester across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for dextester (version 9.9.9).

Malicious package

dextesterRubyGems

Advisory published Feb 3, 2025Updated Sep 24, 2026

dextester is a confirmed malicious RubyGems package (MAL-2025-1010) that executes malicious code on install (malicious version 9.9.9). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in dextester (RubyGems)

MAL-2025-1010

Immediate action

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

gem uninstall dextester

Malicious versions

1 flagged

9.9.9

Indicators of compromise (SHA-256)

14130a52f7496d5380c093d24aabf747ae91475fee89ef5d786fdec521e9b0fa

4431a9f45297880d3159d43460d0645cef0edd47ad980e21e59f9a773f96623f

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for dextester (version 9.9.9).
If you installed it — respond
Remove dextester 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 dextester 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. dextester on RubyGems has been identified as a malicious package (version 9.9.9 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-00552RLUA-2026-07976

References

github.com

Credits

ReversingLabs · finder

Detect & block this

O3 blocks dextester-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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