Exchange Emergency Mitigation Service with new CU Update

This is a big thing in the Exchange world from my POV! I believe this is dropping sometime today (28th September!)

History

Exchange OWA, ECP etc. are exposed online not only for mailbox access, calendar sharing but also are a requirement for hybrid mode sync capabilities.

Vulnerabilities in Exchange this year (ProxyLogon/ProxyShell) have shown how problematic an attack surface this is. The good news is, Microsoft have created a feature for Exchange to help mitigate these attacks in the future via the EM Service!

Defense

How to restore AdminSDHolder Object Permissions using ADSIedit

Ok so the other day “we” as a community put out some guidance around post active directory compromise actions for when you can’t simply nuke the forest from orbit. Well, following on from that a friend asked about how to restore AdminSDHolder permissions? Read more “How to restore AdminSDHolder Object Permissions using ADSIedit” →

Defense

Windows Security Fundamentals & LPE

Introduction

Recently I decided to do the Red Team Operator: Privilege Escalation in Windows Course by Sektor7 (thanks for the recommendation Justin!). I thought I’d write some notes but also create a quick blog covering some of the Windows fundamental areas. It’s easy to actually forget how this stuff is at a detailed level so figured it helps both myself and the world to share a snippet. I’m litterally listening to the course as I type this, I’ve just imported an OVA to vmware workstation so this is litterally live! (I’m 7 video modules in!)

There’s some key parts around Windows Security Architecture that is important to know, the course does cover this off at the start so I thought I’d share a tiny bit of my notes. Read more “Windows Security Fundamentals & LPE” →

Defense

Hardening Office 365 PowerShell Access

Only admins can use PowerShell, right? Wrong! In Office 365 and Azure AD standard users can connect using PowerShell.

In this quick post we are going to look at how to disable users from being able to read other users data using the MSOL cmdlets. (this also appears to limit AzureAD cmdlets access as well)

Disable MSOL Read Access

Run the following command as a global admin: Read more “Hardening Office 365 PowerShell Access” →

Defense

Hafnium / Exchange Marauder High Level IR Help

Ok so John and I have been working on this for a while. We have been working with both customers and industry profesionals and there’s a common theme. Understranding the events from this incident are quite challenging because:

We don’t have sample log output for known bad traffic
The vulns can be used for data theft and/or backdoors (and further actions on target)

Getting guidance out so far on this has been challenging becuase:

There is not a public full kill chain POC to do comaprisons to (i’m ok with that)
We don’t have a pw3d server that has all the indicators from all the routes on

So to try and help people we have made a diagram which we will update as we go.

Essentially you need to perform a weighted analysis to understand if:

You had recon only
You had some SSRF
YOu had SSRF that led to data theft
You had a webshell planted