Note: These issues were last tested with the Steam version shown below: After playing around looking for DLL side-loading issues in System32, I started looking around on my system outside of System32 for any interesting applications I had installed that could be leveraged. One application that immediately caught my eye was Steam, since its installation…
Covenant C2 Infrastructure with Azure Domain Fronting
In a previous post I discussed to setup basic redirectors with Covenant C2. In this post, I hope to show you how to use domain fronting through an Azure CDN for your C2 traffic. A lot of this is based on another post I read from ar-infosec that you can find here. What is Domain…
Privilege Escalation with Canon MX490 Printer Drivers
As part of my “research” I created a tool called “Get-Writable” that will search for .exe and .dll files that are world writable. You pass Get-Writable a directory path, and it will recursively look through every directory to find files. I had Get-Writable start at the “C:\” root to try and find all writable .exe’s…
Unprivileged User Persistence with Zoom
*** UPDATE: It looks like the most recent version of Zoom has fixed the issue of loading an unsigned DllSafeCheck.dll. This persistence technique no longer works. Thank you to @LadhaAleem for bringing this to my attention. See the Patching Zoom.exe section for details on how this can be bypassed. Zoom has been in security news…
DLL Side-loading and Zero-width Spaces
My previous post discussed using appverif.exe and DLL side-loading to execute a payload on a system. The advantage of using a legitimate Microsoft signed binary such as appverif.exe to load and execute your DLL was to bypass anti-virus and application whitelisting. One drawback to this technique is that you are executing appverif.exe outside of its…
DLL Side-loading Appverif.exe
A couple of weeks ago, FireEye published a blog called “Abusing DLL Misconfigurations.” The gist of the blog post is that when an application is executed, it will try and load DLLs for whatever functionality it needs. If the Windows Side-by-side manifest for the application does not have the explicity full path of the DLL,…
Resource Based Constrained Delegation
Earlier this year on a internal penetration test for my employer, I was stuck on Active Directory (AD) escalation. I had gotten a foothold in the environment by cracking a user’s hashed credentials that I had captured through DHCPv6 spoofing. However, the user didn’t belong to any privileged groups and didn’t have local admin privileges…
Constrained Delegation
In previous posts, I have discussed how to setup an AD lab in AWS, attack AD using Kerberoast, and attacking AD with Unconstrained Delegation. In this post I am going to discuss another attack I built into my lab Constrained Delegation. This will all be done through Covenant C2, which I discussed how to setup…
Unconstrained Delegation
One of the weaknesses that I configured in my lab environment was “Unconstrained Delegation.” Systems in an Active Directory (AD) environment can be configured for unconstrained delegation. This means that a system can “delegate”, or impersonate users that authenticate to it. Normally, when a user authenticates to a service running on a system, the user…
Kerberoasting
This post will demonstrate how to perform a “Kerberoasting” attack in an Active Directory (AD) environment. In a previous post, I detailed how to create an AD lab in AWS and how to configure a user with a Service Principal Name (SPN) that will allow for the Kerberoasting attack. Background Information Kerberoasting is an attack…