supply chain event / NVI-00009950 / Revision 1
Malicious code in mev-sandwich-detect (RubyGems)
GitHub lists this malware advisory for mev-sandwich-detect. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
mev-sandwich-detect
source listed= 0.9.1
## Source: amazon-inspector (5d92e0d32c64cdab1627cbfe5bd1d79445d0ff09f4d24336dd9026c02fe46917) 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 t
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-pcpf-mq97-v8pp ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.