Which versions of etheremu.rb are malicious?

The following RubyGems versions of etheremu.rb are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate etheremu.rb if I installed it?

etheremu.rb is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed etheremu.rb — how do I know if it already compromised me?

If etheremu.rb 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 etheremu.rb part of a known attack campaign?

Yes — etheremu.rb is associated with the IN-MAL-2026-021045 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 etheremu.rb across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for etheremu.rb (version 1.0.0).

Malicious package

etheremu.rbRubyGems

Advisory published Oct 5, 2026Updated Oct 6, 2026

etheremu.rb is a confirmed malicious RubyGems package (MAL-2026-17600) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in etheremu.rb (RubyGems)

MAL-2026-17600

Immediate action

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

gem uninstall etheremu.rb

What this malware does

RubyGems runs this gem's native extension script ext/etheremu.rb/extconf.rb during gem install. The script exits without action on CI runners and sandboxes, based on CI environment variables, the hostname, the username and the working directory. It continues if the system uptime is over 30 minutes and the home directory holds .ssh, .gitconfig, .npmrc, .gem/credentials or .bundle. It then decodes a Base64 Ruby payload and forks twice into a detached process. After 20 to 40 minutes the payload downloads http://45.138.12.177:8092/wgkit.tar.gz to /tmp/.w1.tgz with curl, extracts it to /tmp/.w1/, runs wg_install.sh with bash and deletes both. The payload stores the URL XOR-encoded with the key usv\x9a. The Ruby code in lib/ is a decoy. The RubyGems account reqthrottle_3474 published this gem and 41 others with the same loader on 2026-10-05.

The gem's extconf.rb, executed automatically during gem install, contains a base64-encoded Ruby payload that is decoded and eval'd inside a detached forked process. The payload XOR-decodes a hardcoded bare-IP URL (http://45.138.12.177:8092/wgkit.tar.gz), downloads a tarball to /tmp/.w1.tgz over plain HTTP with no pinning or verification, extracts it, and executes the enclosed wg_install.sh via bash. The accompanying native extension C source is an empty stub whose Init function is a no-op, so the extension exists solely as a vehicle to trigger the dropper at install time. The dropper is wrapped in extensive anti-analysis gating: it exits early if CI environment variables are set, if the hostname matches sandbox/firecracker/vagrant patterns, if the username looks auto-generated or contains strings like 'sandbox', 'tester', 'analys', or 'scanner', if the current working directory is under /tmp, /var/tmp, /opt/rubygems, or /workspace, if machine uptime is under 1800 seconds, or if no developer dot-files are present. It further sleeps 20-40 minutes before firing. Execution is gated on the presence of ~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, or ~/.bundle in the installer's home directory, selecting victims whose machines hold SSH keys and rubygems/npm/git publisher credentials for downstream harvesting by the fetched wg_install.sh stage.

The OpenSSF Package Analysis project identified 'etheremu.rb' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

The package executes one or more commands associated with malicious behavior.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

a82ac5d3f021ab23f4f461181f4150c12d672ef421b6f80c10dd8a307178442e

1ae73dae9439612f5e283fda69191f7f0ffae88fab654bb61865e92b8852d9d3

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for etheremu.rb (version 1.0.0).
If you installed it — respond
etheremu.rb is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If etheremu.rb 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. etheremu.rb on RubyGems has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-021045

References

Credits

Amazon Inspector · finder
OpenSSF: Package Analysis · finder
SafeDep · finder

Detect & block this

O3 blocks etheremu.rb-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

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