This months skillz challenge requires us to recover the password from some NTLM hashes, and the tool of choice for doing that is ophcrack.  Ophcrack is available as a windows executable, and also as a live CD but I didn't want to have to boot my computer to a live CD, and I didn't want to have to boot into Windows.

Luckily ophcrack is also available for linux.  Being something of a linux noob I decided that it would be helpful if I produced some instructions for installing ophcrack on linux.  These instructions were written for people using Ubuntu 6.10 (Edgy Eft) because that is what I use and it is what most other linux novices use.  If you're using something else you should find that these instructions mostly work, although you will have to change some things.  If you're running Debian, these instructions should work almost perfectly.

Step One: Get the required libraries.  Ophcrack requires GTK+ and Openssl to run properly.  On Ubuntu you can run the following command to install these libraries

Once the installation is complete, direct your web browser to http://ophcrack.sourceforge.net and download ophcrack-2.3.3.tar.gz

Now open your terminal (command prompt) and go to the directory where you downloaded ophcrack.  Run this command to unpack the tarball.

Change Directory to ophcrack-2.3.3.tar.gz and once inside run
(the dot slash means run the configure script in this directory)
If there are no errors, then run
and finally

Now you should be able to type ophcrack and get the GUI to come up.  Next you'll have to download the rainbow tables from http://lasecwww.epfl.ch/SSTIC04-10k.zip.  The instructions say you have to unpack that zip file in /usr/local/share/ophcrack/10000, but I have found that you can pretty much put it anywhere because when you run ophcrack you'll tell it which folder to look in for the rainbow files.  This file that you're downloading is prett big, by the way, so you can expect it to take a while.

Hope this helps someone...

Awesome, thanks for the tip. I'm also using Ubuntu 6.10 in my virtual lab and I will try this. Also I would like to mention that if you're lazy, you can use ophrack demo version online  to try it out . Here's the following link:

http://lasecwww.epfl.ch/~oechslin/projects/ophcrack/index.php