There’s no doubt that domain accounts with weak passwords can be a serious concern for companies, there are a few ways you can protect yourself against issues like this. The first is to set a domain and local account lockout policy and the second is to enforce password complexity. However if your users are using “Password1” as their password, neither of these steps will protect you.
Why not copy and paste the following into your /etc/john.conf and try them out! Got a suggestion for a rule? Leave a comment! They can then be called with ‐‐rules=Try, ‐‐rules=TryHarder and ‐‐rules=BeBrutal! You can find an explanation of how these rules are built here.
Whilst Hashcat is often provable faster than John the Ripper, John is still my favourite. I find it simple to use, fast and the jumbo community patch (which I recommend highly) comes packed with hash types making it a versatile tool.
One of the features of these tools, which is often unknown or at least under appreciated is the ability to create custom “rules” for teaching the tool how to dynamically generate potential passwords. Since Microsoft implemented “Password Complexity” and this was enforced around the globe, user have made the jump from a password of: password, to the [sarcasm]much more secure[/sarcasm]: Password1.
What are LLMNR and NetBIOS-NS? They’re both methods of resolving hostnames to IP addresses. On your network if you try to contact a system by name first of all DNS will be used, but if that fails LLMNR will be attempted followed by NetBIOS. LLMNR is the successor to NetBIOS and it supports IPv6 and multicast addresses.
On a Penetration Test, once you’ve scored Domain Admin (DA) Access, it’s generally a good idea to take a look at the hashes stored in Active Directory (AD). Not least because it’ll point out all of the weak accounts that you missed on your journey to DA but also because password reuse across accounts may get you into other systems, such as Linux servers or the network infrastructure.
There are a few methods of dumping hashes and every PenTester I expect knows one of these, but I’ve included a few as it’s always good to have a backup plan.