Description

The gem advertises itself as an Ethereum keystore helper but ships a native extension (ext/req_throttle_mini/extconf.rb) whose sole purpose is to execute a malicious payload during gem install. The extconf script base64-decodes an embedded Ruby payload and evals it inside a double-forked, detached child process, then writes an empty Makefile via create_makefile with no C sources present. The decoded payload opens a TCP connection to the hardcoded bare-IP C2 at 45.138.12.177:8090, pipes the socket to /bin/sh via IO.popen and IO.copy_stream in both directions, and reconnects on failure in a loop, giving the operator a persistent remote shell on the installer's host. The dropper is gated by anti-analysis checks: it refuses to fire inside CI, ephemeral or sandbox-shaped hostnames, generated usernames, or analysis path prefixes, requires the presence of developer secrets (~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, ~/.bundle) and sufficient machine uptime, and sleeps 20–40 minutes after detaching before executing to evade install-time scanners. The lib/ module is a thin JSON reader that serves as cover; the native extension ships no real build sources. Package naming targets Ethereum developers likely to hold wallet material and cloud/VCS credentials on their workstations.

The OpenSSF Package Analysis project identified 'eth-keystore-utils' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

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

Mitigation

Aliases

References