snort_stat.pl

入侵检测系统.linux下与MySql连用的例子

#!/usr/bin/perl 
#
# $Id: snort_stat.pl,v 1.3 2000/11/17 05:28:20 jpickel Exp $
# $Revision: 1.3 $
#
# snort_stat.pl is a perl script trying to generate statistical data from every
# day snort log file.
#
# USAGE: cat <snort_log> | snort_stat.pl -r -f -a -h -p -n
#        -r: resolve IP address to domain name
#        -f: use fixed rather than variable width columns
#        -a: snort alert format
#        -h: produce html output
#        -p: portscan log (in syslog now)
#        -n: anomsensor log (in syslog)
#
# or put it in the root's crontab file:
#59      10      *       *       *       root    cat /var/log/authlog | /etc/snort_stat.pl | sendmail root
#
# $Author: jpickel $
# Yen-Ming Chen, <[e-mail]>
# $Date: 2000/11/17 05:28:20 $
# 
# Angelos Karageorgiou, <[e-mail]>
# contributed the DNS resolve and cache
#
# Andrew R. Baker <[e-mail]>
# 2000.03.06 - modifications to read snort alert file
#            - added html output option
#
# Paul Bobby, <[e-mail]>
# 03/13/2000 added scan for portscan detection in logs
#
# Ned Patterson, <[e-mail]> 
# 4/26/2000 - correctly parse "last message repeated" syslog messages
#           - variable column widths for text output
# 
# Ryan Jian-Da Li, <[e-mail]>
# 6/07/2000 - fix the problem of portscan() (add my %s5)
#           - fix the problem of signature matching
#             for the case ' IDS154 - PING CyberKit 2.2 Windows'
#           - enhance portscan(), add port counts
#

use Getopt::Std;		# use Getopt for options
use Socket;			# use socket for resolving domain name from IP
use vars qw($opt_r $opt_f $opt_a $opt_h $opt_p $opt_n);
%HOSTS = ();			# Hash for IP <-> domain name mapping  

getopts('rfahnp') || die "Could not getopts"; # get options in command line
$saddr_len = 15;
$daddr_len = 15;
$timeout = 3;  # for name resolver

# process whatever comes in
while (<>) {
  if ($opt_a) {
    # process data from a snort alert file
    chomp();
    # if the line is blank, go to the next one
    if ( $_ eq "" )  { next; }
    # is this line an alert message
    unless ( $_ =~ /^\[\*\*\]/ ) {
      # comment out this line to avoid some warning 
      # print STDERR "Warning, file may be corrupt.\n";
      next; 
    }
    $a = <>;
    chomp($a);
    unless ( $a eq "" ) {
      # strip off the [**] from either end.
      s/(\s)*\[\*\*\](\s)*//g;
    } else { 
      print STDERR "Warning, file may be incomplete\n";
      next;
    }
    $sig = $_;
    $a =~ m/^(\d+)\/(\d+)\-(\d+)\:(\d+)\:(\d+)\.(\d+)\s
          ([\d\.]+)[\:]*([\d]*)\s[\-\>]+\s([\d\.]+)[\:]*([\d]*)/ox;
    
    $month  = $1; $day   = $2;  $hour  = $3; $minute = $4;
    $second = $5; $saddr  = $7; $host = "localhost";
    $sport  = $9; $daddr = $9; $dport = $10;
  } else {			# If this is a snort log in syslog
    if ($_ =~
	m/^(\w{3}) \s+ (\d+) \s (\d+) \: (\d+) \: (\d+)\s 
        ([\w+\.]*)\s[\w+\/\[\d+\]]*:\s ([^:]+):\s ([\d\.]+)[\:]?
	([\d]*)\s[\-\>]+\s ([\d\.]+)[\:]? ([\d]*)/ox)
      {
	$month  = $1; $day   = $2;  $hour  = $3; $minute = $4;
	$second = $5; $host  = $6;  $sig   = $7; $saddr  = $8;
	$sport  = $9; $daddr = $10; $dport = $11;
      } 
    elsif ($_ =~ m/^(\w{3})\s+(\d+)\s(\d+)\:(\d+)\:(\d+)\s
	   ([\w+\.]*)\s[\w+\/\[\d+\]]*:
	   \sspp_portscan\:\sPORTSCAN\sDETECTED\sfrom\s([\d\.]+)/ox)
      {
	if ($opt_r) {
	  $psaddr = resolve($7);
	} else {
          $psaddr = ($7);
	}
	push @res , [$psaddr];
	push @rescnt , [$psaddr,$8];
	# Not used elsewhere.  Prob not needed. (Need to find out!)
	#          $tot++;
	next;
      }
    elsif ($_ =~ m/^(\w{3})\s+(\d+)\s(\d+)\:(\d+)\:(\d+)\s
           ([\w+\.]*)\s[\w+\/\[\d+\]]*\:
           \sspp_anomsensor\:\sAnomaly\sthreshold\sexceeded\:\s([\d\.]+)\:
           \s([\d\.]+)\:([\d]+)\s[\-\>]+\s([\d\.]+)\:([\d]+)/ox)
      {
        if ($opt_r) {
          $asaddr = resolve($8);
          $adaddr = resolve($10);
        } else {
          $asaddr = ($8);
          $adaddr = ($10);
        }
        $threshold = $7; $sport = $9; $dport = $11;
        push @anores , [$threshold,$asaddr,$sport,$adaddr,$dport];
        next;
      }
    # If a snort message has been repeated several times
    elsif ($lastwassnort && $_ =~ m/last message repeated (\d+) times/) {
      # put the data in the matrix again for each repeat
      $repeats = $1;
      while ($repeats)  {
	push @result, $result[-1];
	$repeats--;
      }
      next;
    }
    else {
      $lastwassnort = 0;
      next;
    }				# Message not related to snort
  }
  # if the resolve switch is on
  if ($opt_r) {
    $saddr = resolve($saddr);
    unless ($opt_f) {
      if ( length($saddr) > $saddr_len ) {
	$saddr_len = length($saddr);
      }
    }
    $daddr = resolve($daddr);
    unless ($opt_f) {
      if ( length($daddr) > $daddr_len ) {
	$daddr_len = length($daddr);
      }
    }
  }
  
  # put those data into a big matrix
  push @result ,[$month,$day,$hour,$minute,$second,
		 $host,$sig,$saddr,$sport,$daddr,$dport];
  $lastwassnort = 1;
}				# end of snort log

# begin statistics
# I should've used $#result + 1 as $total in the first version! :(
$total = $#result + 1;

for $i ( 0 .. $#result ) {
  # for the same pair of attacker and victim with same sig
  # to see the attack pattern
  # used in same_attack()
  $s0{"$result[$i]->[9]:$result[$i]->[7]:$result[$i]->[6]"}++;
  # for the same pair of attacker and victim 
  # to see how many ways are being tried
  # used in same_host_dest()
  $s1{"$result[$i]->[7]:$result[$i]->[9]"}++;
  # from same host use same method to attack 
  # to see how many attacks launched from one host
  # used in same_host_sig()
  $s2{"$result[$i]->[6]:$result[$i]->[7]"}++;
  # to same victim with same method
  # to see how many attacks received by one host
  # used in same_dest_sig_stat()
  $s3{"$result[$i]->[6]:$result[$i]->[9]"}++;
  # same signature
  # to see the popularity of one attack method
  # used in attack_distribution()
  $s4{"$result[$i]->[6]"}++;
  # source ip
  $s5{"$result[$i]->[7]"}++;
  # destination ip
  $s6{"$result[$i]->[9]"}++;
}

# begin report

print_head();
print_summary();
same_attack();
same_host_dest();
same_host_sig();
same_dest_sig_stat();
attack_distribution();
if ($opt_p) {
  portscan();
}
if ($opt_n) {
  anomsensor();
}
print_footer();

# print the header (e.g. for mail)
sub print_head {
  if($opt_h) {
    print "<html>\n<head>\n";
    print "<title>Snort Statistics</title>";
    print "</head>\n<body>\n";
    print "<h1>Snort Statistics</h1>\n";
  } else { 
    print "Subject: snort daily report\n\n";
  }
}

# print the time of begin and end of the log
sub print_summary {
  if($opt_h) {
    print "<table>\n";
    print "<tr><th>The log begins at:</th>\n";
    print "<td>$result[0]->[0] $result[0]->[1] $result[0]->[2]:$result[0]->[3]:$result[0]->[4]</td></tr>\n";
    print "<tr><th>The log ends at:</th>\n";
    print "<td>$result[$#result]->[0] $result[$#result]->[1] $result[$#result]->[2]:$result[$#result]->[3]:$result[$#result]->[4]</td></tr>\n";
    print "<tr><th>Total events:</th><td> $total</td></tr>\n";
    print "<tr><th>Signatures recorded:</th><td> ". keys(%s4) ."</td></tr>\n";
    print "<tr><th>Source IP recorded:</th><td> ". keys(%s5) ."</td></tr>\n";
    print "<tr><th>Destination IP recorded:</th><td> ". keys(%s6) ."</td></tr>\n";
    print "<tr><th>Anomaly detected:</th><td> ". eval '$#anores + 1'."</td></tr>\n";
    print "</table>\n";
    print "<hr>\n";
  } else {
    print "The log begins from: $result[0]->[0] $result[0]->[1] $result[0]->[2]:$result[0]->[3]:$result[0]->[4]\n";
    print "The log ends     at: $result[$#result]->[0] $result[$#result]->[1] $result[$#result]->[2]:$result[$#result]->[3]:$result[$#result]->[4]\n";
    print "Total events: $total\n";
    print "Signatures recorded: ". keys(%s4) ."\n";
    print "Source IP recorded: ". keys(%s5) ."\n";
    print "Destination IP recorded: ". keys(%s6) ."\n";
    print "Anomaly recorded: ". eval '$#anores +1'."\n";
  }
}

# to see the frequency of the attack from a certain pair of 
# host and destination
sub same_attack {
  if($opt_h) {
    print "<h3>The number of attack from same host to same destination using same method</h3>\n";
    print "<table>\n";