Saturday, July 02, 2011

Ophcrack

So you've forgotten your Windows password and need to regain access to your Windows account. There's a open source tool to help you do just that: Ophcrack.

Ophcrack is a Windows password recovery tool based on rainbow tables. It comes in really handy for password auditing and password recovery. It can also be used for less than noble deeds, of course, but that's not the purpose here.

Ophcrack comes in installation packages for Windows and Linux, and there's even a LiveCD version for those that prefer not to install ophcrack on a more permanent basis. The LiveCD also makes a nice addition to the computer technician toolbox as a portable Windows password recovery tool.

Using the Ophcrack LiveCD

Using the Ophcrack LiveCD is a simple matter of popping in the CD you've burned using the ISO from the website, and booting up from the CD. You may need to change your BIOS settings to boot from CD before the hard disk.

Ophcrack LiveCD running
The LiveCD runs automatically so there's nothing specific you need to do but boot the CD, and wait for ophcrack to finish its task.

Caveats

The rainbow tables need to be loaded into memory which means you'll need to have a lot of RAM installed on the machine to run Ophcrack successfully. At least 512MB is need which shouldn't be a problem for recent computers.

Related posts:

Technician's toolbox - malicious software removal tools
Technician's toolbox - system maintenance tools
Technician's toolbox - Ultimate Boot CD