Post Compromise Active Directory Checklist

Nuke it from orbit, it’s the only way to be sure!

Ok, in an ideal world you can re-deploy your entire environment from scratch, but back in the most people’s real world’s that’s not that simple. So, what do we do if we can’t nuke from orbit in a post compromise situation? Well, we need to clean up! This isn’t an exhaustive list, not a total guide. it’s a quick list to make you think about some key common areas and actions that might need to be taken! after all if someone got r00t, who knows what they did! (trust me, most orgs monitoring is a bit naff!)

Guides

What if not everyone is a cyber expert?

Developing a Cyber Roadmap

Ok so this topic comes up a fair bit, but organisations and their management are often looking to ensure they are doing the right thing (no really this is a common phrase I hear with organisations) with regard to cyber security. THe challenge I think quite a few people have is even understanding what that even means. Sure you have a firewall, and antivirus and you had a yearly peneration test of a site that isn’t even touching your corproate network. You thought you were fine, but you keep seeing organisations get ransomared in the news and the board keep asking “are we ok?” so this then leads to a common position of maybe buying more widgets or thinking, well we haven’t been “hacked” so we must be doing ok.

CTF

Abusing AdminSDHolder to enable a Domain Backdoor

If we have high privilege access to a domain, we will likely want to establish persistence with high privilege access. One mechanism to do this is to assign ourselves permissions to the adminSDHolder object in active directory:

Here we have the default adminSDHolder permissions. We are going to add our user “low” in here with modify or full control permissions: Read more “Abusing AdminSDHolder to enable a Domain Backdoor” →

CTF

How to Identify Hashes

Some hashes are obvious but even then, it’s a good job to check. There are a few ways to check a hash outside of manual validation.

Using the Hashcat example list:

https://hashcat.net/wiki/doku.php?id=example_hashes

Using hash-identifier:

https://github.com/blackploit/hash-identifier

Using cyberchef Analyse hash:

https://gchq.github.io/CyberChef/#recipe=Analyse_hash()

Using hash-id:

https://github.com/psypanda/hashID

Using HashTag:

https://github.com/SmeegeSec/HashTag

As you can see there are range of tools available to you, and remember if you want to keep the hashes to yourself you can download Cyberchef and run it locally!

Defense

Infection Monkey Overview

Have you ever wanted to see what would occur in an environment if a worm was a make its way in? I often work with customers to show them about lateral movement from a human operated perspective however sometimes it’s useful for people to visualise this better and to demonstrate what could occur if a worm was set loose. A great tool to help with this is Infection Monkey from Guardicore (https://www.guardicore.com/

High Level View

The process steps are as follows:

Scope Exercise
Prepare Environment
Deploy Infection Monkey Server (Monkey Island)
- Configure Server Credentials
Monkey Configuration
Release Monkey/s
Review
Report

Read more “Infection Monkey Overview” →

Defense

Windows 11 Privilege Escalation via UAC Bypass (GUI based)

Introduction

Ok these are a really simple UAC bypass from a userland GUI perspective. This is about increasing process integrity levels – it’s not about performing LPE from low integrity to high/SYSTEM with no interaction. These clearly work in older version of Windows as well but since Windows 11 will be the current version in the near future I thought it was fun to re-visit these!

And just to be clear, a medium integrity process as an administrator user will have the following privileges:

What we are talking about here is to move to a high integrity process without knowing credentials or having the secure desktop launch. Read more “Windows 11 Privilege Escalation via UAC Bypass (GUI based)” →

Strategy

Cyber Strategy Magic

Strategic this, strategic that

People band strategy around like it’s some sort of mythical beast that requires no knowledge of the subject involved but is done by wizards and executives (it’s just done by people, but I digress) so I thought I’d talk about strategy development.

Now forewarning you might come out of this post thinking… there must be something else… something you are missing as Dan’s not showing any secret magic…. Often what is commonly lacking when looking at strategic execution is effective communication, consensus, and marathon like commitment to deliver on said goals and objectives. Why? Because that part is really, really, hard, if it wasn’t we’d all be sipping Bollinger in the Bahamas.

Know the business

If your first thoughts are to run to Sun Tzu or grab an ISO27001 document then you should probably pause, grab a tea, and take a breath. In my experience cyber security is:

Not a war
Does not require anything to do with the military
The answers are not simply in a book or standard document

People often think that a framework, guide, or standard will give them the answers. Sure, they are often useful tools to help, hell the domain of cyber is broad as hell and there’s so much to do and often so little time, so job aides and not re-inventing the wheel is a good thing, that doesn’t however just mean that with documents you will be in a good position. Read more “Cyber Strategy Magic” →

Defense

Razer Privilege Escalation Vulnerability

“And I looked and behold a pale horse: and his name that sat on him was Death, and Hell followed with him.”

Firstly, Kudos to @j0nh4t for finding this!

I woke up this morning to see twitter fun with a LPE discovered in the Razer driver installation. Basically, when you plug a Razer mouse into a Windows machine, it will download (via windows update) and execute a process as system which has user interaction. This interface includes an install path selector, with this a right click + SHIFT (LULZ) on whitespace will allow you to launch a command prompt/PowerShell window (as SYSTEM).

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

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” →