May 29 2020
In May 2020, I presented some Active Directory security topics in a Trimarc Webcast called “Securing Active Directory: Resolving Common Issues” and included some information I put together relating to the security of AD Group Managed Service Accounts (GMSA). This post includes the expanded version of attacking and defending GMSAs I covered in the webcast.I …
May 27 2020
For most of 2019, I was digging into Office 365 and Azure AD and looking at features as part of the development of the new Trimarc Microsoft Cloud Security Assessment which focuses on improving customer Microsoft Office 365 and Azure AD security posture. As I went through each of them, I found one that was …
Oct 10 2018
At DerbyCon 8 (2018) over the weekend Will Schroeder (@Harmj0y), Lee Christensen (@Tifkin_), & Matt Nelson (@enigma0x3), spoke about the unintended risks of trusting AD. They cover a number of interesting persistence and privilege escalation methods, though one in particular caught my eye. Overview Lee figured out and presents a scenario where there’s an account …
Jan 01 2018
I have been fascinated with Read-Only Domain Controllers (RODCs) since RODC was released as a new DC promotion option with Windows Server 2008. Microsoft customers wanted a DC that wasn’t really a DC. – something that could be deployed in a location that’s not physically secure and still be able to authenticate users. This post …
Nov 24 2017
Many organizations are moving to the cloud and this often requires some level of federation. Federation, put simply, extends authentication from one system (or organization) to another. Gerald Steere (@Darkpawh) and I spoke about cloud security at DEF CON in July 2017. Presentation slides and video are here: “Hacking the Cloud” One of the key …
Aug 10 2017
Active Directory has several levels of administration beyond the Domain Admins group. In a previous post, I explored: “Securing Domain Controllers to Improve Active Directory Security” which explores ways to better secure Domain Controllers and by extension, Active Directory. For more information on Active Directory specific rights and permission review my post “Scanning for Active …
Jun 14 2017
Active Directory Recon is the new hotness since attackers, Red Teamers, and penetration testers have realized that control of Active Directory provides power over the organization. I covered ways to enumerate permissions in AD using PowerView (written by Will @harmj0y) during my Black Hat & DEF CON talks in 2016 from both a Blue Team …
Feb 08 2017
In my previous post, “Detecting Kerberoasting Activity” I explain how Kerberoasting works and describe how to detect potential Kerberoasting activity. The trick to this is understanding what activity is normal in order to filter out the noise and increase the fidelity of the alert. This post describes how to filter from millions of events to …
Feb 05 2017
Introduction Kerberoasting can be an effective method for extracting service account credentials from Active Directory as a regular user without sending any packets to the target system. This attack is effective since people tend to create poor passwords. The reason why this attack is successful is that most service account passwords are the same length …
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