Skip to main content

Using Zerologon to exploit and dump credentials from a Windows 2012 AD server

EDIT: Related video made for a class

The CCDC qualifiers are over now, and my team got 1st! That being said, towards the end of the day, we noticed a lot of suspicious traffic coming to the AD box. While I couldn't figure it out during the competition, it turns out that the red team had been using the zerologon exploit. After we got back, I wanted to learn the ins and outs of this exploit in order to prevent myself from getting hit with it again at the next competition. Turns out, it's relatively easy to set up and execute using Impacket and Risksense' zerologon script. 

 For the testing environment, I have a Windows lab consisting of a 2012 AD, 2019 Email server, 2016 Docker/Hyper-V box, and Windows 10 and 7 machines. This setup is for CCDC prep and is designed to mirror the environments and machines used in the competition. I also have a kali box running on the same network as the Windows machines. This is what staged the attacks on the 2012 AD server. 

 To begin with, I had to do some research and reading on the exploit process and setup. Making sure that the systems hadn't been patched with KB4601357, the Microsoft update that solves the Netlogon vulnerabilities that allow the zerologon exploit to work, and pulling down the newest version of Impacket and the zerologon exploit script to the kali box. Once the scripts and AD were ready to go, I started Wireshark on the AD server and got to executing the first steps of the exploit. 

 Step 1) Using the zerologon exploit script to set the machine password of the domain controller to be empty. 
Step 2) Using Impacket's secretsdump to get the password hashes of the accounts on the domain controller

Step 3) Running wmiexec to establish an SMB connection using the credentials of the Administrator account.


Step 4) Using secretsdump again, this time with the registry values taken from the domain controller.


Step 5) Finally, we can restore the original password to the domain controller, leaving our presence largely unnoticed. 


Here is the Wireshark capture from the AD machine.

In the end, we're left with the credentials for the domain administrator, which allows us to do just about anything we want to the victim. They likely wouldn't even know they had been hit with an attack. I certainly couldn't figure it out beyond some suspicious processes and packet traffic. 

If this is the level of stuff we're seeing in the qualifiers, I'm looking forward to seeing what they hit us with in the next level. Being able to get hands-on with the systems and try to protect and respond to real-time threats has been a great learning experience. It's definitely a little hectic and crazy when you're seeing all these red flags appear and have no idea what's going on, but I love that feeling of excitement and the rush you get when you finally figure out what's happening and how to fix it. The red team definitely kept me on my toes during the competition, and I left with a huge list of things to learn and research further. 

Now, it's time to start preparing for regionals. We're bringing it home!






Comments

Post a Comment

Popular posts from this blog

Using PGPy to encrypt and decrypt files and messages

 PGPy is a library for python that enables the creation, storage, and encryption/decryption of PGP keys and files in python. Recently, in a small project to reacquaint myself with python, I used PGPy for key generation and encryption and decryption. That project can be found in my github at  https://github.com/lpowell . The goal of the project was to use command-line switches to control the program, and to provide basic encryption and decryption capabilities, along with rot13 and base64 encoding.  First, to load in a key use key, _ = pgpy.PGPKey.from_file(keyfilename) . This loads the key from either a binary or ASCII armored file. You can swap out .from_file for .from_blob , if you plan on using a key stored in a string or bytes object rather than a file. In my example code, I pull the key from a file, as I found it to be the simpler method.  Next, you'll need to open a file or create a string or bytes object that contains the message you wish to encrypt. We'll cal...
3 comments
Read more

Using the Ubertooth One to sniff and intercept Bluetooth packets

While researching for my individual video project I came across this tool which allows for the sniffing and interception of bluetooth packets. This article covers some of the basic functionality of an Ubertooth One.  It's really quite interesting to see all the possibilities with devices like these. The tech behind them is very interesting as well. Hopefully, I'll be able to integrate some of this technology into my project video and include a demo of some of the interesting things it can do.
Post a Comment
Read more

Huntress CTF Challenge Writeups: HumanTwo: MoveIt IoC Analysis Challenge

HumanTwo: MoveIT IoC Analysis Challenge The HumanTwo challenge is a malware CTF from the 2023 Huntress CTF. This write-up walks through the initial discovery, de-obfuscation, and solving of the challenge. The actual flag will be redacted from the document, but interested parties should be able to follow the steps and derive it themselves. While the write-up assumes a base level of knowledge regarding the command line and Linux. Most tools and commands will be accompanied by short explanations. Step 1: Initial Analysis To start off, we are given an archive with 1000 files named after their file hash. The hint we are given is that there are minor differences between each file. We also know that HumanTwo relates to the MoveIT vulnerability and exploit. The easy way to progress is to look up articles that tell you about the vulnerability and what stands out in each exploit script. However, I didn’t do that, so I’ll put the process I followed down instead. First, because I knew that...
Post a Comment
Read more