Password Hashes with Python

What You Need

A Kali Linux machine, real or virtual. You could use Windows with Python installed, but it's easier to just use Linux.

Purpose

Generate and crack Windows password hashes with Python.

The same techniques work for Linux and Mac hashes, but thousands of times slower, because Windows uses especially weak hashes.

Getting Test Hashes

In the previous class, we harvested real password hashes from Windows machines with Cain.

Here's a simple test case. A password of 

password
has this hash on Windows machines: 
8846f7eaee8fb117ad06bdd830b7586c
Windows does not use any salt, so every user with the same password has the same password hash.

Note: If you want to calculate more test cases, just go use this website:

InsidePro Hash Generator

The 3rd type of MD4 is a Windows password hash, as shown below:

Calculating Windows NT Password Hashes with Python

In Kali Linux, in a Terminal window, execute this command: 
nano hash1.py
In nano, enter the code shown below:

Save the file with Ctrl+X, Y, Enter.

Running the Program

In a Terminal window, execute this command: 
python hash1.py
Enter a password of password.

You should see a result like that shown below (the memory location may be different):

This is a hash, but it's a binary object and all you see is its memory location. To see the normal result in hexadecimal, add the hexdigest() method like this:

Run the program again. This time you should get the exact hash shown below:

This looks more like a hexadecimal hash, but it's incorrect for Windows passwords. As shown above, the correct NT hash starts with 8846.

That's because the Windows algorithm uses Unicode, not ASCII, to encode the characters.

Modify your program to use Unicode, as shown below. (NOTE: the code for Unicode is "UTF-16LE" with the letters in lowercase, NOT "utf-161e".)

Run the program again. This time you should get the exact hash shown below:

Making a Hash Dictionary

Create a program that calculates the NTLM hashes for all two-digit passwords from 00 to 99.

The last several hashes should look like the image below.

Hints

Making a Loop

Error Encoding an Integer

Converting an Integer to a String

Sources

py-md4

Last revised: 8-4-16