Lately we have seen great articles by @_dirkjan, @tifkin_, @rubin_mor, and @gentilkiwi about utilising Primary Refresh Token (PRT) to get access to Azure AD and Azure AD joined computers.

In this blog, I’ll report my own findings regarding to PRT and introduce the new functionality added to AADInternals v0.4.1.

Multi-factor Authentication (MFA) is nowadays a recommended method for providing extra protection for users. In most cases, it protects users from phishing attacks as the attackers can’t log in even they have user’s credentials.

In this blog, I’ll report my findings on how the Azure AD MFA works under-the-hood, and how I built a custom authenticator app for Android. I also introduce some methods how the rogue administrator can bypass MFA when using user’s compromised credentials.

This post is part ⁵⁄₅ of Azure AD and Microsoft 365 kill chain blog series.

Although on-prem administrators doesn’t usually have admin rights to Azure AD, they can have access to crucial information, such as Azure AD Connect, ADFS, and Active Directory. Administrators of these services can easily get admin rights to Azure AD to manipulate and impersonate users.

In this blog, using AADInternals v0.4.0, I’ll show how to get Global Admin access and how to impersonate users as an on-prem administrator.

This post is part ⁴⁄₅ of Azure AD and Microsoft 365 kill chain blog series.

Global Admin role is the most powerfull administrator role in Azure AD. It is (almost) equivalent to the local system rigths in traditional Windows environment: If you are a Global Admin, there is no security! As a Global Admin, there are no limits what you are allowed to do. For instance, one can easily access others’ data. But why bother, if you can as easily impersonate users?

In this blog, using AADInternals v0.4.0, I’ll show how (as an Global Administrator) to gather information of Azure subscriptions, gather users’ credentials, get system level access to Azure VMs, and how to impersonate users.

This post is part ³⁄₅ of Azure AD and Microsoft 365 kill chain blog series.

Azure AD and Office 365 are cloud services and most information is hidden to the members (or guests) of the tenant. However, there are plenty of information publicly available to anyone.

In this blog, using AADInternals v0.4.5, I’ll show how to gather information of any Azure AD tenant as an insider.

This post is part ²⁄₅ of Azure AD and Microsoft 365 kill chain blog series.

When sharing SharePoint to people outside the organisations or inviting them to Teams, a corresponding guest account is created to Azure AD. Although the created guest account is not a pure insider, it has wide read-only access to organisation’s Azure AD information.

In this blog, using AADInternals v0.4.0, I’ll show how to gather information from Azure AD tenant as a guest user.

This post is part ¹⁄₅ of Azure AD and Microsoft 365 kill chain blog series.

Azure AD and Office 365 are cloud services and most information is available only to the members (or guests) of the tenant. However, there are plenty of information publicly available to anyone.

In this blog, using AADInternals v0.4.0, I’ll show how to gather information of any Azure AD tenant as an outsider.

Sean Metcalf (@Pyrotek3) organised a great webcast at the end of the May 2020. Among other things, Sean introduced a new (to me, at least) attack-vector where an Azure AD administrator can easily get a system level access to any Azure virtual machine of the organisation. Naturally, I had to implement this functionality to AADInternals.

In this blog, using AADInternals v0.3.3, I’ll show how a Global Administator can gain access to any Azure VM of the organisation.

Microsoft changed the location of ADSync encryption keys in Azure AD Connect version 1.4.x. These keys are used to encrypt and decrypt the passwords of “service accounts” used for syncing data from AD to Azure AD. Earlier versions saved the keys in the registry, but currently, it is using DPAPI. Thus, AADInternals couldn’t decrypt the passwords anymore. Luckily, Dirk-jan Mollema described in his great article how the encryption keys could be extracted and used to decrypt the passwords. Using Dirk-jan’s article as a starting point, I decided to implement this to AADInternals.

In my earlier blog, I explained how Azure AD identity federation works under-the-hood. In this post, I’ll be doing the same with Azure AD pass-through authentication (PTA).

Microsoft has published a PowerShell module for their partners to ease and automate operations with their customers. This module is (quite intuitively) called Partner Center. While the module does well what it’s meant to do, it also tells Microsoft what the partners are doing.

OneDrive has a security option to allow syncing only from PCs joined to specific domains. In this blog, using the latest AADInternals toolkit (announced at Black Hat Europe 2019), I’ll show how the domain restrictions can be easily bypassed.

In my earlier blog post I explained how to create a backdoor to Azure AD using an identity federation vulnerability feature I discovered in 2017. In this blog post, I’ll explain how to create a backdoor using Seamless SSO and how to exploit it using forged Kerberos tickets.

On October 25th, I’ll be talking at t2.fi infosec conference in Helsinki. In this blog, I’ll tell what to expect in my Abusing Azure Active Directory: Who would you like to be today? presentation.

In 2017, Oliver Morton introduced a feature he found in Office 365 Active Sync, allowing enumerating the existence of the users based on http status codes. (Update: The “feature” was fixed by Microsoft on mid November 2019). In this blog, I’ll introduce my similar findings on using Microsoft API to enumerate users when Seamless SSO is enabled in Azure AD tenant.

I was honoured to hear that I was accepted to present my AADInternals toolkit at the most respected information security event in the world: Black Hat USA 2019. This is clearly one of my greatest professional achievements so far! In this blog, I’ll briefly introduce what to expect in my demo at Black Hat Arsenal.

Identity federation is regarded as the most secure way to authenticate users to Azure AD. In this blog, I’ll deep-dive to identity federation implementation of Azure AD and point out some serious security issues.

Microsoft (finally!) announced in April 2019 the support for 8-256 character passwords in Azure AD/Office 365. This limit does not apply to users whose passwords are synced from the on-prem Active Directory (or for federated users). In this blog, I tell how to set insanely long passwords (64K+) also for cloud-only users!

On November 2018 Azure AD MFA was down over 12 hours preventing users from logging in to Office 365. Same happened in October 2019 in US data centers. As MFA is usually mandatory for administrators by company policy, they couldn’t log in either. In this blog, I’ll show how to create a backdoor to Azure AD so you can log in and bypass MFA.

For the last couple months I’ve used most of my free time on studying and hacking Azure AD admin APIs. As a result, I’m finally publishing the first (beta) version of the AADInternals PowerShell module.