Which versions of mev-sandwich-detect are malicious?

The following RubyGems versions of mev-sandwich-detect are flagged malicious: 0.9.1. Treat any of these as compromised.

How do I remediate mev-sandwich-detect if I installed it?

mev-sandwich-detect 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 mev-sandwich-detect — how do I know if it already compromised me?

If mev-sandwich-detect 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 mev-sandwich-detect part of a known attack campaign?

Yes — mev-sandwich-detect is associated with the IN-MAL-2026-021362 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 mev-sandwich-detect across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for mev-sandwich-detect (version 0.9.1).

Malicious package

mev-sandwich-detectRubyGems

Advisory published Oct 11, 2026Updated Oct 11, 2026

mev-sandwich-detect is a confirmed malicious RubyGems package (MAL-2026-17790) that steals credentials and exfiltrates sensitive data (malicious version 0.9.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in mev-sandwich-detect (RubyGems)

MAL-2026-17790

Immediate action

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

gem uninstall mev-sandwich-detect

What this malware does

mev-sandwich-detect 0.9.1 is a stub gem whose only functional behavior is install-time code execution. The gemspec declares a native extension, but ext/extconf.rb ships no C/C++ sources and does not build an addon; instead it base64-decodes an embedded Ruby payload and eval()s it inside a double-forked, detached, output-silenced child process during gem install. The decoded payload opens a TCPSocket to the hardcoded host 45.138.12.177 on port 8089 and bridges it to /bin/sh via IO.popen and IO.copy_stream, yielding an interactive shell on the installer's host to the operator of that IP. Execution is gated by anti-analysis checks: the payload exits early if the host appears to be CI, an ephemeral/sandbox VM, a generated analyst username, or running under /tmp or /opt/rubygems analysis paths, and requires uptime over 1800 seconds and the presence of developer-credential artifacts (~/.ssh, ~/.gitconfig, ~/.gem/credentials, ~/.npmrc, ~/.bundle) before dialing out, after sleeping a randomized 20-40 minutes. The lib/ entry point is a 13-line no-op defining only VERSION/build_id/healthy?, and the README is mislabeled as 'bitcoin-rpc-lite'. The native-extension slot exists solely as a lifecycle execution vector for the reverse shell.

Malicious versions

1 flagged

0.9.1

Indicators of compromise (SHA-256)

5d92e0d32c64cdab1627cbfe5bd1d79445d0ff09f4d24336dd9026c02fe46917

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for mev-sandwich-detect (version 0.9.1).
If you installed it — respond
mev-sandwich-detect 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 mev-sandwich-detect 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. mev-sandwich-detect on RubyGems has been identified as a malicious package (version 0.9.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-021362

References

rubygems.org

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks mev-sandwich-detect-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

All malware advisories How O3 detects malware Vulnerability database