/usr/lib/ruby/vendor_ruby/ is in ruby-proxifier 1.0.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/proxifier/
/usr/lib/ruby/vendor_ruby/proxifier.rb
/usr/lib/ruby/vendor_ruby/proxifier/env.rb
/usr/lib/ruby/vendor_ruby/proxifier/errors.rb
/usr/lib/ruby/vendor_ruby/proxifier/proxies/
/usr/lib/ruby/vendor_ruby/proxifier/proxies/http.rb
/usr/lib/ruby/vendor_ruby/proxifier/proxies/socks.rb
/usr/lib/ruby/vendor_ruby/proxifier/proxies/socks4.rb
/usr/lib/ruby/vendor_ruby/proxifier/proxies/socks4a.rb
/usr/lib/ruby/vendor_ruby/proxifier/proxy.rb
/usr/lib/ruby/vendor_ruby/proxifier/version.rb
/usr/lib/ruby/vendor_ruby/uri/
/usr/lib/ruby/vendor_ruby/uri/socks.rb