bitcion-rubyRubyGems

RubyGems runs this gem's native extension script ext/bitcion-ruby/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 'bitcion-ruby' is a one-edit typosquat of 'bitcoin-ruby'. The library has no real functionality (lib/ exposes only a hardcoded 48-word list; ext/bitcion-ruby/bitcion-ruby.c is an empty Init stub). The native extension's ext/bitcion-ruby/extconf.rb runs at gem install time and, before invoking create_makefile, base64-decodes and evals a Ruby payload. The payload performs sandbox/CI/analysis-environment fingerprinting (checks for ~/.ssh, ~/.gitconfig, ~/.gem/credentials, ~/.bundle, ~/.npmrc, requires uptime > 30 minutes, excludes CI environment variables and hostnames matching patterns like 'uvm', 'firecracker', 'sandbox', rejects generated-looking usernames and /tmp or /workspace working directories). On a real developer machine, it forks a detached child that sleeps 20-40 minutes, then curls a tarball to /tmp/.w1.tgz from a URL reconstructed by XOR-decoding a hardcoded hex string with the 4-byte key 'usv\x9a' (overridable via the WG_KIT_URL env var), extracts it, and executes wg_install.sh via bash. The combination of typosquat identity, empty cover functionality, two-layer obfuscation (base64 eval + XOR-encoded URL), environment fingerprinting to evade analysis sandboxes, randomized long sleep, detached forked execution, and fetch-and-exec of a remote shell script constitutes a full install-time remote code execution against developer machines that install the gem.

The OpenSSF Package Analysis project identified 'bitcion-ruby' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

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