require 'msf/core'
class Metasploit3 < Msf::Auxiliary
        include Msf::Exploit::Remote::Tcp
        include Msf::Auxiliary::Scanner
        def initialize
                super(
                        'Name'           => 'My custom TCP scan',
                        'Version'        => '$Revision: 1 $',
                        'Description'    => 'My quick scanner',
                        'Author'         => 'Your name here',
                        'License'        => MSF_LICENSE
                )
                register_options(
                        [
                                Opt::RPORT(12345)
                        ], self.class)
        end

        def run_host(ip)
                connect()
                sock.puts('HELLO SERVER') #when I comment this line (disable it) the script works
                data = sock.recv(1024)
                print_status("Received: #{data} from #{ip}")
                disconnect()
        end
end