Hunting for common Active Directory Domain Services Exploitations

Ok this morning I woke up really really early! I then went on a bit of a KQL thread on twitter, and then IRL work destroyed my plans to play in the lab. However I’m publishing this in its current state [use at own risk etc.] because I think it might help people! So let’s get to it:

These queries can help you identify 3 common active directory attack techniques from logs on a domain controller (this does not rely on ADCS logs etc.)

Defence

What are the top Active Directory Security vulnerabilities I…

Ok so here’s the thing, I do NOT like getting pwn3d! I think you probably would rather your organisation does not too!

What I really don’t want to occur is a ransomware event! They suck, they are like a digital bomb going off.

So I’ve knocked up a quick list to get people thinking (these are NOT all the vulnerabilities I networks you should care about.. but they are some that could lead to a ransomware event!)

Education

Active Directory Attacks – “It’s cold out here”

Scenario

In this scenario it is assumed you do not have credentials, but you do have either adjacent or routable access to an Active Directory Domain Controller and can access common ports/services such as: LDAP, LDAPS, SMB, NETBIOS, KERBEROS, DNS

Education

Active Directory Enumeration with ChatGPT

I’ve not slept well for the last week and my brain is hurting, so I thought I would see if I can take our lovely new SKYNET overload AI “CHATGPT” and make it do all my work for me!

A common vulnerability in systems like Active Directory is where a system administrator writes a password in the description field. So the easy answer to this is DO NOT DO THIS. However during penetration testing we want to check. There’s tons of ways to do this but I thought I’d ask our AI roboto to help, so let’s see!

Hacking

Active Directory Security Cheat Sheet

Ok you need to do some AD Security Auditing or Security Testing/Exploitation, great. Let’s look at some of the common misconfigurations and some tools to help you, a list of things will obviously not be the answer, you will need a method and process to go through from recon/enumeration through to exploitation and impact (effects), but that’s what google is for (and CTFs/Labs)! This post is just me jotting down some notes, hopefully they help defenders think about improving their posture.

Defense

How to restore AdminSDHolder Object Permissions using ADSIedit

Ok so the other day “we” as a community put out some guidance around post active directory compromise actions for when you can’t simply nuke the forest from orbit. Well, following on from that a friend asked about how to restore AdminSDHolder permissions? Read more “How to restore AdminSDHolder Object Permissions using ADSIedit” →

Guides

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

From Zero to DA using ‘PetitPotam’

Introduction

Whilst I was on ‘holiday’ (seriously even when on holiday I almost always must do some work!) a few Windows vulnerabilities were published. Great work by Gilles Lionel, Benjamin Delpy and many many others!

Lab Setup

A Domain Controller
A Separate ADCS Install with Web Enrolment or two DCs one with ADCS installed.
A windows Client Device (non-domain joined)
An attacker device (I used Kali)

You do not need any domain credentials to conduct this exploit chain, so from a network adjacent unauthenticated position you can get DA with the right circumstances (default configuration). Read more “From Zero to DA using ‘PetitPotam’” →

CTF

How to enable NULL Bind on LDAP with Windows…

History of NULL bind

Back in the early Active Directory days NULL bind was actually enabled by default, these days you can get a rootDSE NULL bind out of the box but on Windows Server 2019 you can even disable this!

So why would I want to enable NULL bind? Well, some legacy apps may need it but generally speaking you don’t want NULL bind enabled.

The lesson here is DO NOT copy what I am doing here! Simples! Read more “How to enable NULL Bind on LDAP with Windows Server 2019” →

Defense

Active Directory Effective Permission Auditing

Active directory permissions are a complex beast, at the core of Active Directory you have databases and partitions.

These have access controls lists, there are two types of these:

DACL
SACL

https://docs.microsoft.com/en-us/windows/win32/secauthz/access-control-lists

In active directory auditing these with out of the box tools can be a pain, especially when you are looking to enumerate effective permissions. Luckily a nice chap as made a great PowerShell app which can help you with your auditing activities! Read more “Active Directory Effective Permission Auditing” →