 <p>I'm not aware of any python modules that implement NTLM.</p> <p>But I think this type of authenticated transaction is much more involved than what you're focusing on here. The link you referenced actually contains much more details if you change your starting point from <code>AV_PAIRS</code> structure to the <code>Introduction</code> instead: <a href="http://msdn.microsoft.com/en-us/library/cc236622.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/cc236622.aspx</a></p> <p>That said, in order to tackle this correctly, you must first learn about the <code>struct</code> module, because you'll need to use it to create the NTLM message headers. At the same time, also learn about bit shifting and network-byte-order/host-byte-order, because you're going to need that as well.</p> <p>A simple protocol to practice on would be ICMP. Learn how to read and write that header first, using <code>struct</code> and the others I mentioned. When you're more comfortable, then try and tackle creating and reading NTLM messages.</p> <p>Hope this helps.</p>