Thursday, April 4, 2013

Hacking Windows Password - SAM file [Securing & Cracking]

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(Security Accounts Manager)  >> SAM



SAM file cracking with Ophcrack 

" Hi folks. It happens with many peoples including that you forgot the windows account password and having troubles in Login process OR you simply want to know the Password of your schools or Friends PC ".



Well then I think again its time to crack the Hashes in an easy way. Yeah I know that there are ways to reset the password like RESET WINDOWS PASSWORD but here I'm talking about viewing the password. There is a cool bootable CD called Ophcrack which allows you to crack the hashes using rainbow table and is available in simple GUI.
Its a small linux distribution with a tons of features but very popular for its easy and fast hash cracking feature. I'll cover the detailed features of ophcrack in future article soon.

Basic: Windows uses NTLM hashes to encrypt the password file which gets stored in SAM file. We simply need to target this file to retrieve the password

Tools Required:
  • Ophcrack Live CD. Download from here
  • Time and Patience
Lets get started....

Insert the Ophcrack Live CD and Boot your PC. Make sure the Boot from CD is the first option in the Boot menu at BIOS.
You'll get the Startup menu.
here choose Ophcrack Graphic mode - automatic
After few old loading shots, it'll redirect to the Linux Desktop. There Click on menu > Run
In the pop up box type > ophcrack click ok
Now you can see the ophcrack application windows. Here, click on Load > Encrypted SAM
After that we need to give the path to SAM directory which is by default /mnt/hda1/WINDOWS/System32 click choose
Here we can see the saved hashed now with the username and userid.
Now click on Crack button and wait for the password. Its quick and easy
That's it. It'll show the password now Have fun with the cracked password.

Note: Ophcrack is a live Linux CD, it may not work on all the versions of Windows 7 however its working fine with Windows XP/Vista.








SAM file cracking Offline NT Password & Registry Editor 



You can do this with a small tool called  Offline NT Password & Registry Editor. This utility works offline, that means you need to shut down your computer and boot off your using a floppy disk, CD or USB device (such as pen drive). The tool has the following features:

  • You do not need to know the old password to set a new one.

  • This tool can detect and unlock locked or disabled out user accounts!

  • There is also a registry editor and other registry utilities that works under linux/unix, and can be used for other things than password editing.

How it Works?

Most Windows operating systems stores the login passwords and other encrypted passwords in a file called sam (Security Accounts Manager). This file can be usually found in \windows\system32\config. This file is a part of Windows registry and remains inaccessible as long as the OS is active. Hence, it is necessary that you boot off your computer and access this sam file via the boot menu. This tool intelligently gains access to this file and will reset/remove the password associated with administrator or any other account.
The download link for both CD and floppy drives along with the complete instructions is given below:
It is recommended that you download the CD version of the tool since the floppy drive is outdated or doesn’t exist in today’s computer. After the download, you’ll get a bootable image which you need to burn it onto a blank CD. Now, boot your computer from this CD and follow the screen instructions to reset the password.

Another Simple Way to Reset Non-Administrator Account Passwords:

Here is another simple way through which you can reset the password of any non-administrator accounts. The only requirement for this is that you need to have administrator privileges. Here is a step-by-step instruction to accomplish this task:
  1. Open the command prompt (Start -> Run -> type cmd -> Enter)
  2. Now type net user and hit Enter
  3. Now the system will show you a list of user accounts on the computer. Say for example, you need to reset the password of the account by name John, then do as follows:
  4. Type net user John * and hit Enter. Now, the system will ask you to enter the new password for the account. That’s it. Now you’ve successfully reset the password for John without knowing his old password.
So, in this way you can reset the password of any Windows account at times when you forget it so that you need not re-install your OS for any reason. I hope this helps.

Securing SAM file with SYSKEY

Syskey protects the NT system by further encrypting the NT password database and can be used to prevent book without the knowledge of a special system password.

The Security Accounts Manager (SAM) stores the user passwords in a protected database. The original Windows NT 4.0 database is protected by several techniques:
  • Permissions on relevant Registry keys are set to allow only the operating system access.
  • Permissions on the Registry folders and files are limited. When the system is in operation, the SAM cannot be copied, or accessed directly except by the system and administrators.
  • The passwords are obscured by a one-way function (OWF). This OWF is not decryptable. However, anyone obtaining a copy of the database can use dictionary and brute-force attacks in an attempt to crack or guess the passwords. In a dictionary attack, the same OWF is applied to each word in a dictionary listing, and then the result is compared to the obscured password. A match means the password equals the dictionary word. A brute-force attack compares the password OWF to an OWF of every possible combination of available characters.
Windows NT password-cracking programs have been available for several years. (You can download an evaluation version of the famous LophtCrack tool from http://www.@stake.com.) Although to use them directly against the SAM requires Administrator privileges, a backup of the SAM can be used offline by an attacker. (This is an excellent reason to practice good physical security!) Microsoft developed Syskey to protect the SAM from these types of attacks. Files that support Syskey as well as the program SYSKEY.EXE were incorporated in Service Pack 3 and all later service packs. Syskey uses a 128-bit key to encrypt the password portion of the user database in the SAM. When it was introduced, existing cracking programs could no longer be used to attack the password database.
Unfortunately, additional programs that can be used to provide a crackable database to LophtCrack are now available. These tools, pwdump2 and pwdump3, must be run by a member of the Administrators group in order to be successful. LophtCrack 3.0 does not need these tools; LophtCrack 3.0 can be used directly against a Syskey-protected SAM.
Nevertheless, you should use Syskey to protect the SAM for four reasons:
  • If you use appropriate security practices and limit administrative accounts and require the use of strong passwords, you will mitigate the threat of pwdump2 and Lophtcrack 3.0 being used interactively on your systems. Indeed, if an administrative account has been compromised, there may be little need for cracking passwords in the SAM at all because the administrative account can be used to access any resources protected by DACLs.
  • You have no way of knowing what the attacker is able to deal with, nor what weapons he has in his arsenal. Just because there are armor-piercing bullets should not prevent me from wearing armor if I may be shot at. The bullets fired at me may be of the regular kind, and I will survive the attack.
  • It is always a good idea to layer security on your system. Each problem that you throw in an attacker's way decreases your risk of compromise. If you make attacking your network difficult, many attackers will move on to "lower hanging fruit."
  • For a nonadministrative user to use these tools against your SAM, he must somehow obtain a copy of the SAM and use the tools offline. Good security practices can reduce the possibilities of an attacker obtaining a copy of the SAM. Servers, especially domain controllers, should be physically secured. Emergency Repair Disks and backups of the Registry need to be physically secured. The C:\WINNT\Repair directory (which holds a copy of the Registry when the RDISK program is run to create an ERD) needs to be protected, and Registry files can be removed from this location.

Implementation

The key used to encrypt the passwords is randomly generated by the Syskey utility. This Password Encryption Key (PEK) is itself encrypted with a randomly generated "System" key (Syskey) and stored in the Registry. Encrypting the PEK prevents compromise of the encrypted passwords. If the PEK were stored unencrypted in the Registry, it might be obtained and used to decrypt the passwords. The Syskey must be present for the system to boot. However, now there is a problem: how to protect the Syskey. This protection may be implemented in one of three ways:
  • The Syskey is obfuscated and stored in the Registry. System can boot without administrative action.
  • The Syskey is obfuscated and placed on a floppy disk that must be present when the system reboots. The Syskey is not stored anywhere on the system. The key is stored in a file call STARTKEY.KEY. Do not store the key on an ERD. To do so would be to provide two items needed to attack your system in one location. Do make copies of the disk. Without it you cannot boot your Windows NT system.
  • A passphrase is entered and then used to create encrypt the Syskey. An MD5 cryptographic hash (digest) of the Syskey is stored in the Registry. The password must be entered during system boot to make the system usable.
In either the floppy disk choice or the password choice, the Syskey is not stored anywhere on the system. Therefore, these choices are more secure. If the floppy disk is lost or becomes corrupt, however, or if the password is forgotten, the system cannot be booted.
To apply the additional security provided by using Syskey, follow the procedure listed in Step by Step 1.






STEP BY STEP 1 Applying Syskey Protection to the SAM

  1. Create a backup copy of the Registry prior to completing the additional steps. Be sure to label the backup as pre-Syskey, and store it forever. The only way to recover a Syskey-protected SAM if the Syskey is lost or corrupted is to restore from this pre-Syskey backup of the SAM.
  2. Check the service pack level. Apply the most current service pack. (Service Pack 3 was the first service pack to incorporate Syskey.) Applying the most current service pack adds the code necessary to use Syskey.
  3. If you applied a service pack in step 2, you might want to make another backup of the Registry. Label this one as post-SP and pre-Syskey.
  4. From a command prompt, enter the Syskey.exe command.
  5. In the pop-up window, check the radio button to enable strong encryption.
  6. Select the choice of Syskey operations by selecting the radio button that matches your choice on the windows as shown
    .
  7. If you have selected to enter a passphrase, do so now.
  8. If prompted, provide a floppy disk.
  9. Click OK.
  10. A pop-up window will indicate success.
  11. Reboot the system.
  12. Make a new backup of the Registry and label it post-Syskey.
  13. Repeat the process for each domain controller (the Syskey is not replicated) or Windows NT 4.0 workstation that is to be protected.
     Selecting the Syskey storage method.

The Syskey program may be used to change the Syskey option, or to generate a new Syskey at a later time. It may not be used to bypass Syskey security. If the key is stored on a floppy disk, the disk must be present. If the key is passphrase-derived, the administrator much know the passphrase before being able to rerun Syskey.



Wondering if their is a way to get the local passwords even with encrypted SAM file !!!yes..
but for more visit this links 1 , 2



Sources -::- 1 , 2


 
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