It is very important that we always use secure passwords, the more complex the better, to know if our passwords are secure, we must check its strength, especially the password of our users in Windows either Windows XP, Vista or 7. This is of utmost importance , Since if the password of our user is very weak, it can be easily stolen or discovered by some user or malicious program, and then this could do what he wanted with our data and settings.
One of the things we can do to check if our password is secure or otherwise insecure and easy to find out, or in other words, lacks the necessary strength, is trying to attack it as a hacker would, and we can do that Using a very simple and free program, said program is a LiveCD called OphCrack, because if we know what tools they use, we will know how to defend against their attacks.
But not only can we check the strength of our password, but also, we can use it to recover the user’s password, from someone who is forgetful because he does not remember his password, and therefore can not enter his system. Or recover any of your data or files stored on the hard disk.
Ophcrack, is a program that comes in a LiveCD, very simple to use, since it would be enough to insert it in the PC, and automatically it would start after restarting the PC, once loaded graphically, it would be enough to press the option “to load or Load “so that this one begins to make a attack based on dictionaries, until obtaining the password, as it can be observed in the following image:
This would serve us for the 2 things we can find below, and which I have named above:
1º If we are able to remove the key, it means that its strength was low, and that a malicious user could get it in the same way and with the same software, so it would be advisable to change our key, for one that is composed of a word That does not exist, interspersing uppercase, lowercase, special characters and numbers, after which I would recommend you to do the test over and over, every time you change the password, until you give one that is not detected by the LiveCD.
2º To return the access to the system, to a user who for any reason would not remember his password.
* Depending on the version of Windows that is used, we must use one version or another of LiveCd, since Windows XP does not use the same hash for user authentication, as Windows Vista and 7.
Windows XP: uses the LM hash.
Windows Vista / 7: uses the NT hash.
Unfortunately there is not yet a version of this program for the new operating systems Windows 8 and 10, since its method of encryption of passwords is different and these programs still do not recognize it, as soon as the program allows it to update it.
Anyway, I hope this article has helped you, it has at least allowed me to recover the access to the computer to several clients, I also hope it serves to protect you from malicious users, if you know any other program that serves the Same purpose do not hesitate to comment it as well as your opinion and doubts, I hope you do not use it to do the opposite of what is explained in this article, which is to protect and help, then leave you a link to download such program, many Thank you for your visit and I hope you come back soon.