MAL-2026-17796 Malicious code in staking-apr-fetcher (RubyGems)

The gem declares a native extension whose build script (extconf.rb) decodes a base64-embedded Ruby payload and executes it via eval during gem install. The payload double-forks a detached background process that opens a TCP connection to the hardcoded host 45.138.12.177:8089 and bidirectionally copies between that socket and a locally spawned /bin/sh, giving the operator of that endpoint interactive shell access on the installer's machine. Execution is gated by anti-analysis checks: the payload only fires when the environment does not look like CI, an ephemeral/sandbox VM (patterns matching uvm/firecracker/sandbox/vagrant), a generated analyst user (patterns matching uA\d+/sandbox/tester/analys/scanner), or a known analysis path (/opt/rubygems, /tmp/, /workspace/), and only when system uptime exceeds 1800 seconds and developer-identifying files exist (~/.ssh, ~/.gitconfig, ~/.gem/credentials, ~/.bundle, ~/.npmrc). The gem's advertised identity is a cover story: it is published as staking-apr-fetcher with a staking-related summary, but the README is titled bitcoin-rpc-lite, the extension's generated makefile is bitcoin_rpc_lite_native, no C sources are shipped for that native target, and the Ruby library (lib/staking_apr_fetcher.rb) is an inert stub defining only VERSION/build_id/healthy?. The package has no legitimate functionality; its sole purpose is to deliver the install-time backdoor.

The OpenSSF Package Analysis project identified 'staking-apr-fetcher' @ 0.9.1 (rubygems) as malicious.

It is considered malicious because:

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