A simple guide on how to use the Ophcrack password recovery program.
The popular password recovery program Ophcrack is quite possibly one of the best recovery programs I have ever used. Its ease of use and simple wording make it so that even people who have difficulty using computers can use it.
Ophcrack recovers your passwords by having the program run upon boot up of your computer. This allows the CD program to run before your operating system. The program, when directed to recover your password, goes into the root directory, where the computer stores its passwords in hashes. Hashes are passwords that have been encrypted. Once the program has found the hashes, it needs to decrypt them back to normal text. It does this by using a type of video file called a Rainbow Table. With the use of Rainbow Tables, the program can recover your password in a very fast manner. The program will play the Rainbow Table, and it will try and find a match in the hashes that the computer has given you, and the hashes that that particular Rainbow Table has in it.
Using this technique, password recovery using the program Ophcrack can be completed anywhere from a few seconds for some passwords up to 5-8 minutes for most. Compared to other password recovery programs, this is a massive improvement, and the best part is that Ophcrack is free to download.
To use Ophcrack, here are some simple guidelines and directions in order to properly use it:
1. Download the Ophcrack .ISO image from the website, or other sites. You can download it from the following link:
2. Now that you have the .ISO image, you also will need a .ISO CD burning program. These can be found all over the web as both freeware and shareware. Here is the link for the one I personally prefer:
3. Burn the .ISO image onto a blank CD.
4. Now that the CD has the Ophcrack program on it, you can use the CD, but to use Ophcrack effectively, you should also consider downloading different rainbow tables for it. Rainbow tables are available for free download, and some of the more in depth tables you can purchase from the Ophcrack website.
5. Once you press the power button on your computer to turn it on, press the right key to get into BIOS mode. For most computers, the default is F2. Once your in the BIOS mode, you must change the order in which your computer boots things from. Normally, most computers will first boot up the hard drive so that it may begin its operating system. You must change the first thing that boots to the CD drive so that Ophcrack begins running before your operating system.
6. Now that you are running off the Ophcrack CD, it will load up. This may take a minute or so, and you may see your monitor blinking on and off for a few moments. Once everything is running, it will continue to a desktop look alike where you may begin recovering passwords.
Once you begin to feel comfortable with the Ophcrack program, you will see that it runs very smoothly and very efficiently. I believe that every person that works in IT should have a copy of this program, as well as some of the Rainbow Tables, so that the next time an employee of the company forgets or loses their password, you will save a lot of time by just using this great program.