/usr/lib/ruby/ is in ruby-net-ssh-multi 1.1-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/net/
/usr/lib/ruby/vendor_ruby/net/ssh/
/usr/lib/ruby/vendor_ruby/net/ssh/multi/
/usr/lib/ruby/vendor_ruby/net/ssh/multi/server.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/version.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/dynamic_server.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/session_actions.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/pending_connection.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/channel_proxy.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/subsession.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/channel.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/session.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi/server_list.rb
/usr/lib/ruby/vendor_ruby/net/ssh/multi.rb