A few of my favorite MDCA features

TL;DR – Just a few of my favorite MDCA features, which you may already be paying for.

I previously mentioned my strong belief that Sentinel and MDC are best buddies. Similarly, I firmly belief MDCA (Microsoft Defender for Cloud Apps) is definitely a member of the MDE squad. If you are using MDE (Microsoft Defender for Endpoint) and you haven’t tested MDCA, you may be surprised how well they work together and guess what? You may already be paying for it!

MDCA, which was previously known as MCAS (Microsoft Cloud App Security), is a CASB (I am going for a record number of acronyms in this post!), which stands for Cloud Access Security Broker. In an over simplified way, the job of a CASB is to enforce security policies. I think MDCA does that and more, and quite honestly, I am continuously discovering new features. In this post I am going over a quick list of some of my favorite features.

Cloud Discovery / Shadow IT

MDCA can discover applications (31,000 on the last count) through various means:

  • As part of the MDE squad, it can integrate with MDE to get data from managed Windows devices, as shown above. This integration also gives you the power to block apps as well. More on that a little later.
  • Log Collector over syslog or FTP and various Docker images are available.
  • Can also natively integrate with leading SWGs (Secure Web Gateways) and proxies, such as Zscaler, iboss, Open Systems, Menlo Security, Corrata, etc. (no need for Log Collectors)
  • You will also see data from the Cloud App Security Proxy, so that means even if it’s not from a managed Windows device, you will get some data from the other devices as well, as shown below.

And I can also create policies that will alert for Shadow IT, such as the ones shown below:

Block Apps

There are a few ways apps can be blocked as well. One of those is through the integration with MDE. I configured a few applications as unsanctioned for testing purposes, as shown below.

So, when I try to access one of those applications from a managed Windows device, I receive the following error:

And it’s not just Edge! See the error message below from Chrome on the same device:

I can also “Generate block script” for various types of appliances, as shown below:

Here is an example based on the applications I’ve set as unsanctioned:

Ban OAuth Apps

Solorigate anyone? MDCA can help you monitor OAuth apps in various ways, as shown below, where you can discover and either ‘approve‘ or ‘ban‘ risky apps.

Once you mark an app as ‘banned’, the Enterprise Application is updated with “Enabled for users to sign-in?” set to “No”. I also noticed that the application disappeared from “MyApps” for those users that were previously assigned to the application.

You can also create policies that will automatically revoke risky apps, as shown below.

Conditional Access App Control

So, technically this is done with another member of the squad, Conditional Access. The same Conditional Access we know and love that controls initial access is also capable of controlling access within a session when it works with MDCA.

I have a few very powerful policies, as shown below.

I won’t cover the first one “Confidential Project Falcon Sensitivity Label Policy“, because I dedicated a full blog post to that one, you can find it here: Restrict downloads for sensitive (confidential) documents to only compliant devices.

The second “Block sending of messages based on real-time content inspection – wow” is a way to prevent Teams messages based on a specific word and in this case from a non-compliant device. In my example, I want to block the word ‘wow’. Maybe ‘wow’ is my new super secret project and I only want people discussing it from compliant devices. So, if you try to send a message with the word ‘wow‘ from a non-compliant device, you would see the following:

Yes, the message is customizable :). And it prevents the message from being sent, as shown below:

Next, “Block sending of messages based on real-time content inspection – SSN“, it’s very similar to above, except, it’s not just a word, but rather a pattern, an SSN pattern. So, the user would see a similar message and it won’t be sent either.

Note: This is not real data, it’s just sample data used for DLP testing purposes.

Next, “Block upload based on real-time content inspection – CCN and SSN“, it’s similar, but now I am checking for content within files that are uploaded, whether it’s being attached to an email, being uploaded to a SharePoint site, etc.

Finally, “Proxy – Block sensitive files download – SSN”, it’s similar, but upon download.

Information Protection

Ok, so you saw some information projection above, but there’s more!

One of the policies above is “File containing PII detected in the cloud (built-in DLP engine)“, which automatically labeled a file, based on the contents, as shown below:

Threat Protection

There are some pretty powerful possible controls within this area, as shown below:

But I have chosen to show you how this “Mass download by a single user” policy works. Note that I have adjusted some of the values, so I can generate an alert for my test.

Because I know you may be thinking ‘but this is all within Microsoft services‘. So, check this out! This alert was generated by a user that downloaded files from an AWS S3 bucket, as shown below:

Honorary Mention 1 – App Governance

App Governance is technically an add-on, but I think it’s pretty cool, so I am including it. Note that this is now under the new Cloud Apps menu in security.microsoft.com.

App governance uses machine learning and AI to detect anomalies in OAuth apps. It can alert you on applications from an unverified publisher that have been consented to by your users. It can also alert on overprivileged applications, with permissions that are not even used, and various other anomalies.

Honorary Mention 2 – Security Posture for SaaS Apps

Security Posture for SaaS apps is super new, still in preview, but I can see the incredible potential. Currently, only available for Salesforce and ServiceNow, but I am sure more are to come. It makes recommendations on security best practices within those SaaS applications, as shown below:


I’ve only described some of my favorite features within MDCA. MDCA also integrates pretty closely with MDI (Microsoft Defender for Identity) and various other Microsoft and 3rd party security services. There is a lot more to MDCA than I included here, but I hope this post gives you an idea of how this service can help you secure your organization.

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