Rapid Active Directory Security Testing of Windows Server 2022…

Introduction

Ever needed to test active directory in a hurry? Well, here’s some common commands to test active directory domain services. In this post today we are going to focus on DNS and username enumeration, there are however a range of weaknesses you want to look for:

SMB Null Session/Guest Access
LDAP Null Bind
Sensitive Information Disclosure
Weak Password Policies
Unpatched Software Vulnerabilities

Active Recon

Port Scanning and Service Fingerprinting

nmap -p- -sC -sV -Pn -v -A -oA ecorp.local.txt 192.168.1.22

Domain Name and Domain Controller Enumeation

Guides

Hacking Windows Server 2022

WIndows Server 2022 is RTM! I love new operating systems, but also with the new, what is old? There will be loads of new blogs and articles on new features of Server 2022 however I wanted to see what mischief we can have with it! So I’ve decided to start looking at common vectors and exploits (from the fun to the serious) so that we can see how much of the world has changed (or not!)

So let’s take a look. The first thing I did was to offline replace stickykeys with cmd.exe – yes this method still works. But as lots of people will realise, you neeed physical access to the disk (well you don’t if you have access to someone’s vcenter you don’t!) but also the reg key methods also work! We can still backdoor RDP – here’s a script to disable NLA, Enable RDP, configure the firewall rules and set the registry keys to backdoor the system (clearly for lab use only!)

https://github.com/mr-r3b00t/RDP_Backdoor

Defense

Windows Remote Management 101

Windows Remote Management is easy if you are using a domain joined machine and have a CA. But what if you are off the domain and you want to connect to WINRM that has an HTTPS listener? (by default WINRM uses HTTP on TCP 5985, you can clearly chop out the TLS related configs in the example scripts and they will work for plain old WINRM)

This is useful from a sysadmin and penetration testing/red team perspective. Now obviously you could export the certificates and import them into your store, however that’s more work. So, let’s look at how we ignore revocation, CA name and Computer Name checks.

WinRM via HTTPS (self-signed)

Defense

Penetration Testing

Overview

Penetration testing is the activity of conducting security testing with the aim of identifying and exploiting vulnerabilities to identify strengths and weaknesses. I include strengths because I believe it’s important for security testing to promote both positive and negative findings. I also think that there is a huge mis conception with what penetration is, what it helps with and how to best get value from a penetration test.

My definition isn’t too far from the NCSC one: https://www.ncsc.gov.uk/information/check-penetration-testing

A penetration test is a security assurance activity, but it’s one of many activities that I recommend people conduct. This is however largely only adopted by the few, for many a penetration test is a compliance tick box, either from a regulatory or contractual requirement.

When looking at a system a penetration test is not usually the most efficient starting point, especially if it’s from a black box perspective. Read more “Penetration Testing” →

Guides

What do you need to be Cyber Leader?

Introduction

What does it take to be a cyber leader? How do we address a broad challenge we have in today’s business world?

There are a huge number of organisations whereby the leadership do not have domain expertise in cyber and related disciplines. There are decision makers who are having to best guess. On the other end of the spectrum, we have thousands and thousands of people trying to “break into cyber” yet they face largely insane entry requirements with the forementioned adding things to junior and entry level role which include:

Must have a CISSP (CISSP requires 5 years’ experience and is an Information Security certificate that is very broad and not very deep, it also covers a range of areas that in my opinion aren’t even required for many cyber security capabilities inside organisations)
Must have a Certified Ethical Hacker (this exam includes remember historic malware dates, is that really what we need from our leaders?)
Must have a very large level of experience of be from an existing cyber role

Defense

Why are ransomware attacks so devastating? – Part 1

Introduction

“Ransomware is a major issue!”

Hang on maybe we need to re-phrase that:

“Weak security postures are a major issue!”

or perhaps.. why not both!

I’ve been working with digital technology management for over 20 years, I started out when I was a kid (literally) fixing people’s PCs in their offices, removing malware, improving configurations, writing batch file menus, and playing games. As time has gone on technology has shrunk and continually become more and more of our everyday lives.

Back in 2003 I responded internally to MSBlaster, an SMB worm that had a devastating effect for the time, by today’s standards it was child play, however I remember saying “it’s a good job it didn’t delete everything whilst it was here.” (Or something very similar. Post NACHI/Blaster my friends and I were talking about how worse it could get. Fast forward in time and it’s much worse. Yet when I look at networks, they don’t look very different to how they did back in the 2000s.

Despite a multi-billion-dollar cyber security industry, it seems daily that organisations are succumbing to “cyber-attacks” which commonly include ransomware. Why are they successful and why are they so impactful? Well, let’s take a look! Read more “Why are ransomware attacks so devastating? – Part 1” →

Defense

Audit NTDS.DIT using DSINTERNALS

Ok this assumes you know how to get the NTDS.DIT and SYSTEM registry hive out from a domain controller, if you don’t go looking, we might have blogged a few ways to do that! Now then, firstly, let’s Install DSInternals. From PowerShell 5 onwards you can simply run:

Install-Module -Name DSInternals -Force

You will likely need to set your execution policy:

Set-ExecutionPolicy -ExecutionPolicy Unrestricted

Now to dump the hashes we use: Read more “Audit NTDS.DIT using DSINTERNALS” →

Defense

Dumping Credentails with MIMIKATZ and Passing the Hash (PTH)

I kid you not, I forget the commands, so I thought, hey let’s write a small blog post on credential dumping and pass the hash.

To achieve this we need: Debug privileges on a single machine or we need access to a disk that does not have full disk encryption. We also need the password to be re-used.

Mimikatz

Ok for this demo I’m going to run with the out of the box release for Mimikatz on a domain joined windows PC with Defender disabled.

To gain system we launch mimikatz from an admin shell and run:

privilege::debug

token::elevate

Now we are SYSTEM we access a range of high privilege level areas. Read more “Dumping Credentails with MIMIKATZ and Passing the Hash (PTH)” →

Defense

Hacking Guide – AESREPRoast and Kerberoasting

Kerberos Pre-Authentication Hash Retrieval and Cracking

We can enumerate active directory to find accounts that do not require pre-authentication. There’s a simple way of doing this using Rubeus:

.\Rubeus.exe asreproast /format:hashcat

We can see there is a vulnerable account that has Kerberos Pre-Authentication disabled.

This hash can be loaded into hashcat and possibly cracked (the hash in the screenshot is weak on purpose) Read more “Hacking Guide – AESREPRoast and Kerberoasting” →

Defense

Executing/Creating a process via WMI Methods

WMI is an awesome technology capability for Windows administration, I’ve been using WMI since the Windows 2000 era, I’ve written WMI based scripts/tools to defeat malware, yay, however with any tool the use can be for good and for evil!

This post is going to focus on Win32_Process:Create (there are other methods as well!) Read more “Executing/Creating a process via WMI Methods” →