This document pools several awesome tools and blog entries together (see "Resources" at the end of this doc) in an attempt to automate the process of getting an initial foothold on a network in a situation where you have no valid credentials.
Ok, so one weird thing I'm trying to figure out is if I install ntlmrelay as the first tool we'll use, these steps seem to work ok:
git clone https://github.com/CoreSecurity/impacket.git /opt/impacket
cd /opt/impacket
pip install .