NT Gatekeeper: Using John the Ripper

I've heard a lot of great comments about the John the Ripper (JtR) password cracker, but the tool appears to be rather complex. Can you explain how to set up JtR and how to use it for basic password quality tests?

When you download JtR (which is available for free from http://www.openwall.com/john), be sure that you download the Win32 binaries. Then, extract the complete john-16w.zip file to your computer's hard disk.

Like other password-cracking tools (such as L0phtCrack), JtR operates on the password hashes stored in the Windows NT SAM database, which resides in the \winnt\repair\sam._ file. However, JtR can't retrieve the password hashes from the SAM database. To retrieve the hashes, you need a tool such as pwdump2.exe, which you can download from the BindView Web site at http://razor.bindview.com/tools/desc/pwdump2_readme.html.

To use pwdump2.exe to extract password hashes from the SAM, first extract the pwdump2 zip file, then run the Pwdump2 command from the directory that contains pwdump2.exe. For example, the command

pwdump2 >D:\john\run\passwd.lanman

dumps all password hashes from the SAM database of the system on which you're running the tool to a file called passwd.lanman and stores the file in the D:\john\run directory. If you use Notepad to open the passwd.lanman file, you'll see output that contains one line for every user account in the SAM, as Figure 3 shows. A set of colon-separated alphanumeric values that represent the password hash follows each user account name. . . .