First we can try to Roast all Users in the Current Domain (May be Noise), Kerberoast All Users in a Specific OU (Good if Organization has all Service Accounts in a Specific OU). When you sit down at your workstation, and press Ctrl+Alt+Del to log on and enter your credentials, your machine begins the process of authentication.

Yep you’re right. Now with PowerView in memory on a Domain-Joined Machine we can simply run. Shout out to Benjamin Delpy, the InfoSec community would be nothing without you. m0chan – Authenticates – CRM Server – authenticates on behalf of m0chan – DB Server to fetch information.

“Red Siege”, the Red Siege Logo, and “I am Offensive” are federally registered trademarks owned by Red Siege, LLC. Similar to Kerberoasting there is a very useful python script from the Impacket library that helps request TGT's for accounts with Pre-Auth disabled from Linux. When the first domain controller in a domain is created, a user named krbtgt is created with a random password. Below are some examples. >>

I am going to try formulate all examples I have saw from other articles on exploiting this, there can be quite a lot of different use cases. Well Kerberos tickets are also stored in LSASS so to dump them you also need to elevate to local admin, you could run it as normal user but you will only dump the tickets for your current context hence if you want to dump other users credentials I advise you elevate. In the case of an HTTP service, the service ticket is embedded in the headers of the HTTP request. 12 0 obj Pre-Authentication is the first step in Kerberos Authentication and it’s main role is to try prevent against brute-force password guessing attacks. 27 0 obj <<

Configure all Privileged or Sensitive Accounts with `Account is Sensitive and Cannot be Delegated. xڽ��N�0��~

Kerberos, or Cerberus, is a three-headed dog in Roman mythology that guards the gates of the underworld, preventing inhabitants there from escaping.

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Just like Kerberoasting, AS-REP Roasting can be done from both Windows & Linux and I will cover Linux in this section even though I highly recommend you do this from a Windows Machine and/or a Domain Joined Machine for ease of access. Here we are at the last section, big GG’s if you are still with me through all this, It has taken me nearly 2 days to write this. In order for this Silver Ticket to be successfully created, the AD computer account password hash for adsmswin2k8r2.lab.adsecurity.org needs to be discovered, either from an AD domain dump or by running Mimikatz on the local system as shown above (Mimikatz “privilege::debug” “sekurlsa::logonpasswords” exit).

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I want to take this time to talk about what exactly leaves Kerberos tickets (TGS/TGT’s) in LSSAS on Windows Machines as this had me confused for a while, due to the wide range of logon-types available. He covers the basics of Kerberos authentication and then show you how the trust model can be exploited for persistence, pivoting, and privilege escalation. Cloud Reference Architecture – Virtual Data Center (VDC), Microsoft Teams Audio Conferencing & Toll Numbers, How To Start Your Own Blog – Microsoft MVP Story, Cloud Reference Architecture CRA P3 – Enterprise Structure, Cloud Reference Architecture CRA P1 – Foundation. Without them the hacking community wouldn’t be the same. I am aiming to approaching this writeup with a medium-high level overview, if you would like a true low level understanding of Kerberos I advise you look into harmj0y & Sean Metcalf. Typcially during Pre-Auth a user will enter his creds which will be used to encrypt a time stamp and the DC will decrypt it to validate that the correct creds were used. 10/11/2017; 8 minutes to read; In this article Security Update for Windows Authentication Methods (3178465) Published: August 9, 2016 | Updated: October 11, 2016. Set Account is Sensitive and Cannot be Delegated as this will prevent an attacker from lateral movement using said account/kerberos ticket. There are numerous ways to enumerate service accounts and find Kerberoast targets so I will cover a few below, both from Windows Machines & Linux Machines. Le protocole Kerberos est issu du projet « Athena » du MIT, mené par Miller et Neuman.

This allows you to retain your privilege model and to not have over-privileged servers. This is the same token information the KDC included in the user’s TGT. If so, then join Tim Medin as he walks you through how to attack Kerberos with ticket attacks and Kerberoasting. /Filter /FlateDecode

endobj Now we are armed with target accounts let’s boot up Rubeus. 03/04/2017

However as previously mentioned sometimes users may authenticate with something other than Kerberos, like NTLM therefore they do not pass a TGS ticket through. Whereas with Golden Ticket you forge a TGT with the krbtgt hash which grants you access to every service and/or machine in the entire Domain. One example of when an AP_REP message would be generated is in the case of a client that requests (in the AP_REQ message) that a service prove its identity through a process known as mutual authentication. You may have already noticed me chatting about Pass-The-Ticket above or PTT but I figured it required it’s own section as it can be extremely useful for not only importing Silver/Golden tickets into a current session but also dumping current Kerberos tickets. And if you do not understand something feel free to drop me a DM and I will do my best to help :).

You can also reflectively load it from PowerShell but I will be covering .NET in greater detail in a future article. Learn how your comment data is processed. Microsoft Security Bulletin MS16-101 - Important.

However as this is normal operation you will get ALOT ALOT of Event 4769 & Event 4770 alerts, AS-REP roasting is an attack that is often-overlooked in my opinion it is not extremely common as you have to explicitly set Accounts Does not Require Pre-Authentication aka DONT_REQ_PREAUTH. Common accounts with the SPN (Service Principal Name) set are service accounts such as IIS User/MSSQL etc. << /S /GoTo /D (Outline0.1) >> The S4U request is simply if we want to abuse the account trusted for Constrained Delegation but impersonate any users context to access said service. This request is subject to replay attach, so Microsoft added another field, which is called (Kerberos Pre-Authentication).

When the password is reset, then when client gives the TGT to a domain controller, DC needs to re-authenticate the client as the TGT uses password somehow for authenticity. This is called Protocol Transition, The reason we need S4U2Self is because the S4U2Proxy extension requires a valid TGS ticket to be passed too it from the requesting user before it goes onto request a TGS for Service 2 - Shenaniganslabs.io calls this “evidence” and I believe that’s a really good way to put it.