Removing Azure Enterprise app consented permissions

After installing the appropriate PowerShell modules you can connect to the Microsoft Graph with PowerShell using the command:

connect-graph

as shown above. First thing to remember is that this process can’t be completed in the Power ISE, you’ll need to do it elsewhere (here, using Windows terminal). The second thing to note is that you can specific the scope with which you to connect. Thus, in this case, the scope will be Files.ReadWrite.All and Sites.Readwrite.all. The scope is in effect the permissions the current user will be given when they connect to the Microsoft Graph. This allows you to only provide permissions for exactly what you need.

During the connection process you’ll be asked to consent to the permissions just requested, as shown above. If you simply select Accept here, you are just consenting for the current user. However, if you check the Consent in behalf of your organization option you’ll be providing these permissions to ALL users in your tenant! For now, only consent will be granted for the current user. However, be very, very careful consenting for the whole organization as I will illustrate.

You can now happily go off and perform whatever actions you need to using PowerShell for the Microsoft Graph.

With security in mind, I went to have a look at where these permissions just consented to actually appear. You’ll find them by opening the Azure Portal and navigating to Azure Active Directory as shown above. From here, select Enterprise applications from the menu on the left.

From the screen that appears ensure All applications is select from the menu on the left. Then on the right, locate and select Microsoft Graph PowerShell as shown.

From the screen that now appears, select Permissions from the menu on the left as shown. On the right you’ll then be able to select either Admin consent or User consent.

Because the permissions assigned were only for a single user, the User consent item will show these to us as shown above. This list of permissions matches those consented to when connecting to the Microsoft Graph.

The right hand most column in this display, Grant by, has a hyperlink to show the number of users with this assigned permission.

If you select any of these hyperlinks, you’ll see a list of users, on the right, that have been assigned this permission appear on the right as shown above.

Can you see the problem yet? No? Well…….how do you REMOVE or revoke a permission here?

From what I can determine, you can’t remove the permissions via the portal. If you select Review permissions menu option you’ll see a item displayed from the right as shown above. If you select the option This application has more permissions that I want and basically told to use PowerShell to revoke all permissions for this application as well as being provided with the code to do so.

The issue is that even after you disconnect from the Microsoft Graph, having completed any scripting, those consented permissions remain in place i.e. they are NOT rescinded. This means that if the user account with these permissions to the Graph is compromised then that attacker has access to the Microsoft Graph and potentially lots of sensitive areas in a tenant, especially if the permissions have been added to over time. Imagine how much WORSE it gets if permissions were consented tenant wide, rather than to an individual user?

Selecting that little check box in the above Permissions requested dialog, which I see MANY people do without thinking, can really give you a security headache by opening up your Microsoft Graph permissions for EVERY user in the tenant!

Thus, best security practice is going to be to remove these permissions when they are no longer required as well as limiting who has them initially. Personally, I’d remove them after each interaction so I don’t forget and leave a potential attack vector.

To make doing all that a little easier, I have gone out and created a script that you’ll find in my Github repo:

https://github.com/directorcia/Office365/blob/master/graph-adappperm-del.ps1

If you run the script, it will first check whether the Azure AD PowerShell module is loaded. If it is, it will then ask you to login to your tenant. Then it will display a list of all the Azure AD applications in your tenant and allow you to select the ones you want to change (yes, you can select multiple Azure AD apps if you want) as shown above.

In this case, Microsoft Graph PowerShell application is selected.

You’ll then be prompted to select whether you wish to select Admin consent and/or User Consent permissions. You can select both here if you wish by using the CTRL and/or SHIFT key when making selections (i.e. just like when you use Windows Explorer).

If you selected User consent, you’ll then be prompted to select the users you want. Again, multiple selections are available if offered.

You’ll now be prompted to confirm you wish to delete these permissions for these users.

Those permissions will be removed and the script will continue to work through the rest of your selections.

In this case, because there were no Admin consented permissions for this application we receive a notification line as shown in above output.

If you now return and have a look at the permissions for that app in the portal, you should see they have all been removed as shown above.

Leaving users with standing permissions to something as powerful as the Microsoft Graph is not best security practice. It is therefore important to regularly review these and remove what is not required. If you need those permissions again in eth future, after they have been removed, you can always re-consent to them when you next connect to the Microsoft Graph.

End to End email protection with Microsoft 365–Part 6

This is part of a series of articles about email security in Microsoft 365. Please check out previous articles here:

End to End email protection with Microsoft 365 – Part 1

End to End email protection with Microsoft 365 – Part 2

End to End email protection with Microsoft 365 – Part 3

End to End email protection with Microsoft 365 – Part 4

End to End email protection with Microsoft 365 – Part 5

These articles are based on a model I have previously created, which you can read about here:

CIAOPS Cyber protection model

designed to help better explain expansive security included with Microsoft 365.

Email reporting and auditing

It’s now time to look at all the logging that occurs during even the simply process of receiving and viewing an email. For starters there is:

Message tracing

and

Message trace in the modern Exchange admin center

Message trace in the Security & Compliance Center follows email messages as they travel through your Exchange Online organization. You can determine if a message was received, rejected, deferred, or delivered by the service. It also shows what actions were taken on the message before it reached its final status.

There is also reporting options like:

Mail flow insights in the Security & Compliance Center

and

Mail flow reports in the Reports dashboard in Security & Compliance Center

as well as:

Microsoft 365 Reports in the admin center – Email activity

If you want to specifically look at email security there is:

Email security reports in the Security & Compliance Center

as well as:

Defender for Office 365 reports in the Reports dashboard in the Security & Compliance Center

and

Reports for data loss prevention (DLP)

I have also spoken about the importance of the Unified Audit Logs (UAL) in Microsoft 365:

Enable activity auditing in Office 365

Unified Audit Logs in Microsoft 365

and you need to ensure that these have been enabled so that you can:

View mailbox auditing

Starting in January 2019, Microsoft is turning on mailbox audit logging by default for all organizations. This means that certain actions performed by mailbox owners, delegates, and admins are automatically logged, and the corresponding mailbox audit records will be available when you search for them in the mailbox audit log.

Here are some benefits of mailbox auditing on by default:

Auditing is automatically enabled when you create a new mailbox. You don’t need to manually enable it for new users.
You don’t need to manage the mailbox actions that are audited. A predefined set of mailbox actions are audited by default for each logon type (Admin, Delegate, and Owner).
When Microsoft releases a new mailbox action, the action might be automatically added to the list of mailbox actions that are audited by default (subject to the user having the appropriate license). This means you don’t need to monitor add new actions on mailboxes.
You have a consistent mailbox auditing policy across your organization (because you’re auditing the same actions for all mailboxes).

With this auditing enabled you can do things like:

Reporting mailbox logins

and

Search the Office 365 activity log for failed logins

as well as

Audit Office 365 user logins via PowerShell

Many of the reports that you find in the Microsoft 365 Admin area can be scheduled to be sent via email per:

Scheduling compliance reports

Apart from auditing and security you can also do more typical things like:

Viewing mailbox usage

Viewing Email apps usage

The availability of all this data is covered here:

Reporting and message trace data availability and latency

typically being 90 days.

User reporting and auditing

For information more specifically about user logins into the service and the Identity container, the best place to look is in Azure Active Directory (AD).

What are Azure Active Directory reports?

Find activity reports in the Azure portal

Azure Active Directory sign-in activity reports – preview

Audit activity reports in the Azure Active Directory portal

and if you want use PowerShell

Azure AD PowerShell cmdlets for reporting

Device reporting and auditing

There are lots of options when it comes to monitoring and reporting on devices. Apart from what is offered locally you also have:

Intune report

Create diagnostic settings to send platform logs and metrics to different destinations

Manage devices with endpoint security in Microsoft Intune

You can even get telemetry data and analytics reports from your desktop applications via:

Windows Desktop Application Program

Aggregated data reporting and monitoring

As you can see with all the options above, it is easy to get to information overload trying to keep up with all those signals. Luckily Microsoft provides a range of services to aggregate all this for you to make monitoring and report easier.

The first is Microsoft Cloud App Security services:

Cloud App Discovery/Security

Microsoft Cloud App Security overview

Microsoft Cloud App Security data security and privacy

There are plenty of reasons why you really should have Microsoft Cloud App Security in your environment:

A great security add on for Microsoft 365

Office 365 Cloud App Discovery

Next, is Microsoft Defender for Endpoint that will aggregate security and threat information for devices in your environment and make it available in a single console.

Overview of Microsoft Defender Security Center

Microsoft Defender Security Center portal overview

Microsoft Defender for Endpoint

Microsoft Defender for Endpoint evaluation lab

Finally for me, there is Azure Sentinel, which I see as really the ultimate hub for event reporting, monitoring and alrtign across the whole service.

Another great security add on for Microsoft 365

Introduction to Azure Sentinel

Azure Sentinel is a service that growing in features rapidly:

A couple of new additions to Azure Sentinel

Stay ahead of threats with new innovations from Azure Sentinel

Summary

Hopefully, all this gives you some insight into all the auditing and usage data that Microsoft 365 captures during any interaction within the service. One of the biggest benefits is also how this information is integrated between services, especially those that aggregate information lime Microsoft Cloud App Security and Azure Sentinel. This means you don’t have to crawl through individual log entries, you can use a dashboard and drill down from there. I also like the fact that all of these services and data are accessible using a scripting tool like PowerShell if you want to automate this further.

Remember, throughout this six part series I’ve just looked at what happens when a single email is delivered and view with Microsoft 365. If you expand that out to all the services and capabilities that Microsoft 365 provides you can hopefully get a better appreciate of the protection it provides in place for your data on many different levels.

The call to action for readers is to go away and implement all the security features that Microsoft 365 provides. This may of course vary by the license that you have. You should then consider what additional security offerings the Microsoft cloud stack can offer that makes sense for your business, then implement those. Remember, security is not a destination, it is journey.

End to End email protection with Microsoft 365–Part 5

This is part of a series of articles about email security in Microsoft 365. Please check out previous articles here:

End to End email protection with Microsoft 365 – Part 1

End to End email protection with Microsoft 365 – Part 2

End to End email protection with Microsoft 365 – Part 3

End to End email protection with Microsoft 365 – Part 4

These articles are based on a model I have previously created, which you can read about here:

CIAOPS Cyber protection model

designed to help better explain expansive security included with Microsoft 365.

In the previous part we had arrived at the stage where the user had successfully logged into a Windows 10 device.

At this point, the user is most likely to launch Outlook to read their emails. Visually the process is going to look like:

The email has been delivered from outside the Microsoft 365 Service to the Data container. The User has authenticated themselves via various methods to the Device container. An App on the device will now apply the User authentication to allow the App access to Data container to retrieve the email so it can be displayed to the User.

The focus for this articles will be the access of the App (Outlook) to the email Data as mentioned.

When it comes to the security of this interaction the place to start is to ensure that the App (Outlook) is supported and up to date. The first thing to check is:

What version of Outlook do I have?

and make sure that it is supported by the Service:

Office versions and connectivity to Office 365 services

Given that most Microsoft 365 plans come with a subscription to Office on the desktop, the assumption here is that it is fact supported. There are various ways to:

Download and install or reinstall Microsoft 365 or Office 2019 on a PC or Mac

but for simplicity the assumption will be that it is installed and maintained using:

Deploy Microsoft 365 Apps with Microsoft Endpoint Configuration Manager

It is obviously very important to ensure that all applications that access secure data are updated regularly.

Choose how to manage updates to Microsoft 365 Apps

How to install the latest applicable updates for Microsoft Outlook (US English only)

The assumption will be that, via whatever method, the Microsoft Office desktop application are indeed up to date.

When the Outlook app runs, it will do so on the device, which will be typically connected to the public Internet. this means it is going to need top copy data from the secure Data container in the above model to the secure Device container which lives in another location.

Transferring secure data across an insecure medium like the Internet involves a lot of technology. A lot of them you can read here:

Exchange-Outlook Protocols Documentation

however the most relevant is probably:

How Exchange Online uses TLS to secure email connections

Microsoft 365 is also moving to TLS 1.2 in Office 365 for further security.

Once the email data has traversed from the Data container in Microsoft 365 to Outlook on the user Device is typically stored in an OST file on the local machine.

Introduction to Outlook Data Files (.pst and .ost)

This OST data file is not itself encrypted but the location in which it resides on the device is encrypted using BitLocker.

Outlook incorporates a number of in-built security features including:

Outlook blocked access to the following potentially unsafe attachments

Security Behavior of the Outlook Object Model

Protected Properties and Methods

New feature in Office 2016 can block macros and help prevent infection

Plan security settings for VBA macros in Office 2016

Enable or disable macros in Office files

Overview of the Junk Email Filter

Emails in Outlook will also be protected by Defender for Office 365:

Zero-hour auto purge (ZAP) in Exchange Online

Safe Links in Microsoft Defender for Office 365

Safe Attachments in Microsoft Defender for Office 365

Yet another layer of protection will be:

Microsoft Defender for Endpoint

including technologies like Attack Surface Reduction (ASR) which I have detailed previously:

Attack surface reduction for Windows 10

Further data protection can then be provided by Windows Information Protection (WIP) per:

Protect your enterprise data using Windows Information Protection (WIP)

“Windows Information Protection (WIP), previously known as enterprise data protection (EDP), helps to protect against this potential data leakage without otherwise interfering with the employee experience. WIP also helps to protect enterprise apps and data against accidental data leak on enterprise-owned devices and personal devices that employees bring to work without requiring changes to your environment or other apps.”

For example, if WIP was implemented, it would prevent user saving corporate attachment to non-compliant devices. Perhaps like a USB key.

Further still there is:

Azure Information Protection

which protects information no matter where it travels.

So even when a copy of the email is sitting in Outlook on the desktop it is and can be protected by a wide variety of technologies in Microsoft 365.

If we now take a step back and have a look at a summary of many of the protections we have been talking about so far we would see something like shown above. Remember here that all we have focused so far on is email! Many of these protections will in fact protect information as well as the protection it provides for email. The take away is, in a nutshell, there is a lot of stuff protecting user data provided by Microsoft 365.

Although there is a lot of protection capabilities in Microsoft 365, many of the protection services are either not enabled by default, require unique policies or have generic policies. It is important for each organisation to evaluate what their security requirements are (i.e. what they want to protect) and then implement the services available to them in Microsoft 365 to meet these requirements. The take away is, if you want all the protection features available in you need to configure them, they don’t all magically work to your requirements out of the box!

Also, simply enabling or configuring all these services is something that will need to be continually reviewed and adjusted over time. We’ll also cover that topic in some details in upcoming articles.

Now you can enable all these services and make everything super secure but doesn’t provide absolute security, because that simply doesn’t exist. It will certainly mitigate the majority of threats out there but it still means that the whole environment needs to be monitored constantly to ensure nothing is getting through. Remember, every time we cross a container boundary above, logs are generated. Where and how to use these logs will be the subject of the next part in this series, so stay tuned.

End to End email protection with Microsoft 365–Part 6

End to End email protection with Microsoft 365–Part 4

This is part of a series of articles about email security in Microsoft 365. Please check out previous articles here:

End to End email protection with Microsoft 365 – Part 1

End to End email protection with Microsoft 365 – Part 2

End to End email protection with Microsoft 365 – Part 3

These articles are based on a model I have previously created, which you can read about here:

CIAOPS Cyber protection model

designed to help better explain expansive security included with Microsoft 365.

In previous parts, we covered how an external email was delivered into the Microsoft 365 service and all the protections that it passed through until it finally came to rest in the Data container (user’s inbox) ready to be viewed. The next step in the process will therefore for the user to fire up their device to read the email. This article will therefore focus on the protections available for that device.

For the sake of simplicity we’ll focus on that being a modern device running at least a Windows 10 Professional. Of course, email from Microsoft 365 can be viewed on just about any devices these days, Windows or not, and all of these have unique and overlapping protections. However for the sake of brevity let’s just focus on the more common Windows 10 device for now.

A range of hardware device protection is available and recommended including:

and should already be in place to protect the device.

We will also assume that the Windows device is fully up to date

How to keep your Windows computer up to date

The device in question should also already live inside the Device container as shown in the above model. This is largely achieved thanks to being joined to Azure Active Directory (AD):

Azure AD joined devices

Join your work device to your organization’s network

Tutorial: Join a new Windows 10 device with Azure AD during a first run

When that device is turned on we want it to complete the:

Secure Windows boot process

Once the machine has booted and before the user has logged into the machine, thanks to being Azure AD joined, Microsoft Endpoint device policies have already been pushed and implemented on that machine per:

Manage device security with endpoint security policies in Microsoft Intune

Such policies could be enforcing disk encryption, implementing Attack Surface Reduction (ASR) and so on.

Importantly, you can also enforce device compliance policies to ensure devices meet a security standard before they are allowed to access any data:

Use compliance policies to set rules for devices you manage

All of this is achieved via:

Microsoft Endpoint Manager

which I have also written a whole series of articles to help provide a better understanding of the role that it plays with device security. You can read these articles here:

Modern Device Management with Microsoft 365 Business Premium–Part 1 of 10

Assuming that the device has booted and successfully completed all the protection processes associated with that have been correctly applied, it is now time for the user to login to that devices. This means that we now follow the User connector in our model shown above, into the Service container from outside, then onto the Device Container and so on.

The user’s identity is protected inside the Microsoft 365 service via a variety of mechanisms. When logging into a Windows 10 device they will typically need to provide their account and password details that were set up with the service. However, best practice would now be to use Windows Hello for Business.

Windows Hello for Business Overview

Windows Hello addresses the following problems with passwords:

Strong passwords can be difficult to remember, and users often reuse passwords on multiple sites.
Server breaches can expose symmetric network credentials (passwords).
Passwords are subject to replay attacks.
Users can inadvertently expose their passwords due to phishing attacks.

Many mistakenly believe that the Windows Hello PIN is all that protects a users access to device and the service when at login. That is in fact not the case as Windows Hello leverages the TPM hardware to provide a highly secure login to the service.

Why a PIN is better than a password

How Windows Hello for Business works

These days just a login and password are not enough to secure any identity, you MUST implement Multi Factor Authentication (MFA). Why? As Microsoft will tell you:

Your password doesn’t matter, but MFA does! Based on our studies, your account is more than 99.9% less likely to be compromised if you use MFA.

Your Pa$$word doesn’t matter

All your creds are belong to us!

So MFA, along with a number of other recommended steps, are what can be done with Microsoft 365 to protect user identity.

Five steps to securing your identity infrastructure

Windows Hello for Business requires all users perform multi-factor authentication prior to creating and registering a Windows Hello for Business credential. Importantly, Windows Hello for Business replaces passwords with strong two-factor authentication on PCs and mobile devices. This authentication consists of a new type of user credential that is tied to a device and uses a biometric or PIN. Many don’t appreciate that correctly configured Windows Hello for Business DOES provides MFA when users access their devices, while making the device login process seamless. If you are however still concerned about this ‘single credential’ being compromised then you can also implement:

Multifactor Unlock

It is also important to remember that MFA is provided FREE on all Microsoft 365 accounts and support a variety of methods including authenticator apps, hardware token and more.

Enable multi-factor authentication for free

Once the user has correctly provides a login and password, then completed their MFA challenged (or equivalent thanks to Windows Hello for Business) they would then be subject to Azure AD Conditional Access.

It is important to remember that Azure AD Conditional Access is evaluated AFTER a successful login from a user, not before! This means that it can’t be used to block things like Password Spray Attacks.

Conditional Access policies at their simplest are if-then statements, if a user wants to access a resource, then they must complete an action.

Conceptual Conditional signal plus decision to get enforcement

What is Conditional Access?

For example, user account access can be blocked if it comes from outside a specific country or region.

Conditional Access: Block access by location

and enforcing MFA

Conditional Access: Require MFA for all users

Conditional Access: Require MFA for administrators

Once any Conditional Access policies have been met the user will be able to login to their device. At this point additional Microsoft Endpoint Manager policies will be applied to that specific account now logged in. Such policies could restrict applications the user has access to, limit Windows functionality and so on.

Remember, all of these protections have taken only during the user has logging onto their device. They have not as yet run an application like Outlook to read the inbound emails. That is what is going to happen next and I’ll cover that process in the next part of the series, so stay tuned.

End to End email protection with Microsoft 365–Part 5

End to End email protection with Microsoft 365–Part 3

This is part of a series of articles about email security in Microsoft 365. Please check out previous articles here:

End to End email protection with Microsoft 365 – Part 1

End to End email protection with Microsoft 365 – Part 2

These articles are based on a model I have previously created, which you can read about here:

CIAOPS Cyber protection model

designed to help better explain expansive security included with Microsoft 365.

So far, email has travelled from ‘somewhere’ on the Internet (outside the service) through various layers of protection, which I have already spoken about previously. It has now finally come to ‘rest’ in the data container inside the Service (Microsoft 365) as shown above. However, even at ‘rest’, data is still protected thanks to the capabilities in Microsoft 365.

Remember, that as yet, there has been no user interaction with the data so far. The email has simply been delivered to the users inbox awaiting them to log in and view it.

While the email sits inside the data container in Microsoft 365, protection is being provided by Zero Hour Purge (ZAP). As Microsoft says:

In Microsoft 365 organizations with mailboxes in Exchange Online, zero-hour auto purge (ZAP) is an email protection feature that retroactively detects and neutralizes malicious phishing, spam, or malware messages that have already been delivered to Exchange Online mailboxes.

which you can read more on here:

Zero-hour auto purge (ZAP) in Exchange Online

This means that even after an email is delivered to a users inbox it is constantly being monitored as to whether it is phishing, malware, spam or something otherwise nefarious. If it is detected as such, then appropriate action is taken. Such action can be determined by an administrator during configuration things like spam policies per:

Use the Security & Compliance Center to create anti-spam policies

So this means that not only does Microsoft 365 scan inbound and outbound emails as they pass through the service, they continue to scan all emails once delivered thanks to the fact that they reside inside the actual Microsoft 365 service at all times. This is a big benefit over third party scanning services that only do so as the email passes through their filters, no inside the actual inbox.

You can therefore rest assured that if a malicious email is detected at any stage in Microsoft 365, and assuming you have enabled ZAP, you’ll be protected.

While sitting on servers in Microsoft data centers all sorts of additional protections are in place such as being encrypted at rest:

Encryption in the Microsoft cloud

Encryption Risks and Protections

In addition to using volume-level encryption, Exchange Online, Skype for Business, SharePoint Online, and OneDrive for Business also use Service Encryption to encrypt customer data per:

Service encryption

The best reference for all the extensive Microsoft cloud protections is the:

Service Trust Portal

You also might want to take a look at virtual tour of a Microsoft datacenter:

Take a guided tour of a Microsoft datacenter to learn how Microsoft delivers your cloud services

and read about how Microsoft meshes all these datacenters together to provide the Microsoft 365 service:

Azure global infrastructure

Azure facilities, premises, and physical security

Where your data is located

Hopefully now you are comfortable with the fact that the protection Microsoft 365 provides for your inbound email data (as well as all your other data) is rigorous, from the moment that it enters the Microsoft 365 service until it sits ready for a user to interact with it.

The next stage in the journey will be for a device (i.e. PC) to connect to the Microsoft 365 service and then for a user to log into that device and run an app, like Outlook, to read the delivered email. Spoiler alert – there is even more protection involved here and I’ll start covering that in upcoming articles, so stay tuned for a closer look at what happens during user interaction with the data inside Microsoft 365.

End to End email protection with Microsoft 365–Part 4

End to End email protection with Microsoft 365–Part 2

This is part of a series of articles about email security in Microsoft 365.

End to End email protection with Microsoft 365 – Part 1

These articles are based on a model I have previously created, which you can read about here:

CIAOPS Cyber protection model

designed to help better explain expansive security included with Microsoft 365.

In the previous part of this series I spoke about DNS and Exchange Online Protection (EOP) and the role they play in email security as well as how to configure these in your service. I haven’t as yet spoken about the best practices settings that you should employ. The initial objective here is to help you understand the flow as well as all the security services that can be utilised in Microsoft 365 to better help you protect your data.

If you look at the above diagram, you’ll see that data is flowing via the email connector in and out of our Microsoft 365 environment (the ‘Service’). Through which, so far, we have talked about DNS and EOP, now it is time to move onto Defender for Office 365 (D4O). However, just before we do let, me point out somethings that you may not appreciate. Firstly, via the process far, inbound email data has not yet come to rest. That is, it hasn’t as yet been stored inside a users mailbox, it is still being ‘processed’ by the security feature set of Microsoft 365 (i.e. the ‘Service’). Secondly, and more importantly for security considerations, what we have examined so far largely only ‘scans’ the data and makes security decisions as data passed through that service. It doesn’t generally continue to protect the data once it has been processed by that service. For example, with spam filtering inbound emails are scanned by the anti spam service in EOP, appropriate action taken based on the policies in place but then the data exits the service. Once an email has exited the anti spam service in EOP it will no longer be scanned by the service. To distinguish these type of security services going forward, let’s refer to them as ‘pass through’ security services being that they only handle the data once during its transit through a connector.

So after DNS and EOP have ‘processed’ the inbound email it is time for Defender for Office 365 (D4O) to do it’s job.

Defender for Office 365 is an add-on to existing plans like Microsoft 365 Business Basic and Business Standard but included in Microsoft Business Premium. Interestingly, it is not part of Microsoft 365 E3 but is part of Microsoft 365 E5. In short, we’ll assume the plan here is Microsoft Business Premium.

Defender for Office 365 also has two plans

Gains with Defender for Office 365, Plan 1 (to date):

Technologies include everything in EOP plus:

Safe attachments

Safe links

Microsoft Defender for Office 365 protection for workloads (ex. SharePoint Online, Teams, OneDrive for Business)

Time-of-click protection in email, Office clients, and Teams

Anti-phishing in Defender for Office 365

User and domain impersonation protection

Alerts, and SIEM integration API for alerts

SIEM integration API for detections

Real-time detections tool

URL trace

So, Microsoft Defender for Office 365 P1 expands on the prevention side of the house, and adds extra forms of detection.

Gains with Defender for Office 365, Plan 2 (to date):

Technologies include everything in EOP, and Microsoft Defender for Office 365 P1 plus:

Threat Explorer

Threat Trackers

Campaign views

Automated Investigation and Response (AIR)

AIR from Threat Explorer

AIR for compromised users

SIEM Integration API for Automated Investigations

So, Microsoft Defender for Office 365 P2 expands on the investigation and response side of the house, and adds a new hunting strength. Automation.

The above is from The Office 365 security ladder from EOP to Microsoft Defender for Office 365.

Microsoft Business Premium includes Defender for Office 365 P1, while Microsoft 365 E5 includes Defender for Office 365 P2.

Unlike EOP, you’ll also note that Defender for Office 365 extends protection actually into the data container as well as providing initial scanning of data as it passes through the service. This effectively means that Defender for Office 365 is monitoring email data inside user email boxes and providing additional protection even after an item is delivered. This is very important to appreciate because once most emails are delivered they are generally no longer protected by scanning technologies like anti-spam policies, especially third party offerings. Therefore, a major of value of using Microsoft 365 is that it can ensure the security of data even after it has been delivered using technology like Defender for Office 365.

Another point that the above diagram illustrates is that Defender for Office 365 largely applies only to inbound email data. all the policies in Defender for Office 365 are focused at emails being delivered to, not from, mailboxes.

Finally it is also important to note that previous components in the data flow chain impact Defender for Office 365, DNS probably being the more influential. This is why it is so important to ensure that you have your DNS records (especially SPF, DKIM and DMARC) configured correctly because their impact is more than on a single service in Microsoft 365.

Defender for Office 365 is composed of three unique components:

– Safe Attachments

– Safe Links

– Anti-Phishing

Safe Attachments

As Safe Attachments in Microsoft Defender for Office 365 notes:

Safe Attachments uses a virtual environment to check attachments in email messages before they’re delivered to recipients (a process known as detonation).

In short, it will open suspect attachments in a virtual environment and check to see whether they activate any malicious activity such as encrypting data (i.e. cryptolocker attack), changing registry settings and so on.

Safe Attachments protection for email messages is controlled by Safe Attachments policies. There is no default Safe Attachments policy. Please note that, there is NO default Safe Attachments policy by default! Thus, ensure you have set one up if you are using Defender for Office 365.

Set up Safe Attachments policies in Microsoft Defender for Office 365

Safe Attachments will continue to provide protection even after the data has been delivered. This is because the maliciousness of the attachment is evaluated not only at the time the user opens it but also continually as they sit as data in users mailbox. Thus, you need to consider Safe Attachments as protection both during transit and at rest. This is generally different from the role of EOP.

I will also briefly note here that Safe Attachments protection extends beyond just emails, but I’ll cover that in a later article.

Safe Links

As Safe Links in Microsoft Defender for Office 365 notes:

Safe Links is a feature in Defender for Office 365 that provides URL scanning and rewriting of inbound email messages in mail flow, and time-of-click verification of URLs and links in email messages and other locations.

In short, it routes any link clicked on in an email through a reputation proxy to ensure that it is safe prior to proceeding. This provides protection against malicious content, downloads, phishing and more.

Safe Links settings for email messages

How Safe Links works in email messages

Safe Links can be configured to provide customised protection:

Set up Safe Links policies in Microsoft Defender for Office 365

Safe Links will continue to provide protection even after the data has been delivered. This is because the maliciousness of links is evaluated not only at the time the user clicks on them but also continually as they sit as data in users mailbox. Thus, you need to consider Safe Links as protection both during transit and at rest. This is generally different from the role of EOP.

I will also briefly note here that Safe Links protection extends beyond just emails, but I’ll cover that in a later article.

Anti-phishing

Phishing is when attackers try to trick users into providing secure details in an effort to compromise that account. A common ‘trick’ is to attempt to impersonate a ‘familiar’ email address and try to have the recipient take an action that will result in an account compromise.

Protection via Defender for Office 365 is again provided by a policy:

Exclusive settings in anti-phishing policies in Microsoft Defender for Office 365

Anti-phishing will continue to provide protection even after the data has been delivered. This is because the maliciousness of email content is evaluated not only at the time the user views them but also continually as they sit as data in users mailbox. Thus, you need to consider Anti-phishing as protection both during transit and at rest. This is generally different from the role of EOP.

In addition to the above Defender for Office 365 P1 also provides:

Threat Explorer and Real-time detections

while Defender for Office 365 P2 additionally provides:

Threat Trackers

Automated investigation and response (AIR) in Microsoft Defender for Office 365

Attack Simulator in Microsoft Defender for Office 365

Summary

Inbound email data flows into Defender for Office 365 after it has been processed by EOP. Here additional protection policies are applied. All of these policies can be configured by the user and have capabilities that extend into protecting data even after it has been delivered. This means that a major benefit of Defender for Office 365 is that it not only scans email data during inbound transit but also while it is being stored in the users mailbox over the life of that data item for both current and future threats.

It is also important to note that many of the Defender for Office 365 do not have appropriate default policies in place and it is up to the user to configure these to suit their environment.

The inbound email data has yet further protection configurations to be applied to it after being processed by Defender for Office 365 thanks to the capabilities of Microsoft 365. Please follow that process with the next article:

End to End email protection with Microsoft 365–Part 3

Need to Know podcast–Episode 262

Security is big this week and you’ll get it all here. Our cloud news will provide you with all the latest information you’ll need to understand the Solar Winds attack. in this episode we also speak with Daniel Chronlund around Conditional Access. Daniel shares his extensive knowledge around this service and how it can improve your security posture. He also has some great scripts available on his Github repository, so check them out!

I take this opportunity to wish listeners happy holidays. Stay safe and thanks for all your support in 2020. Onwards to 2021 we go, hi ho, hi ho.

This episode was recorded using Microsoft Teams and produced with Camtasia 2020.

Take a listen and let us know what you think – feedback@needtoknow.cloud

You can listen directly to this episode at:

https://ciaops.podbean.com/e/episode-262-daniel-chronlund/

Subscribe via iTunes at:

https://itunes.apple.com/au/podcast/ciaops-need-to-know-podcasts/id406891445?mt=2

The podcast is also available on Stitcher at:

http://www.stitcher.com/podcast/ciaops/need-to-know-podcast?refid=stpr

Don’t forget to give the show a rating as well as send us any feedback or suggestions you may have for the show.

Resources

A moment of reckoning: the need for a strong and global cybersecurity response

Analyzing Solorigate, the compromised DLL file that started a sophisticated cyberattack, and how Microsoft Defender helps protect

SolarWinds Post-Compromise Hunting with Azure Sentinel

Ensuring customers are protected from Solorigate

Microsoft Defender for Office 365 investigation improvements coming soon

A “quick wins” approach to securing Azure Active Directory and Office 365 and improving your security posture

4 ways Microsoft 365 is improving the experience for Mac users

Sleeping Tabs in Microsoft Edge: Delivering better browser performance

Guest Access in Yammer using Azure AD B2B is now in preview!

Stay current with in-demand skills through free certification renewals

Microsoft Clarity | Free behavioral analytics product for website managers

CIAOPS Patron community

End to End email protection with Microsoft 365–Part 1

I’ve talked about the

CIAOPS Cyber protection model

before and you can see it above.

Now it is time to start applying it directly to Microsoft 365 to help understand the security Microsoft 365 provides and what can be configured to provide enhanced security.

I’ve therefore started by breaking the Email connector from my model into two components, Inbound and Outbound, as shown above. The left hand side (outside the box) is the Internet, while inside the box on the right hand side, is Microsoft 365.

Outside the box, on the Internet, there are three user configurable items: SPF, DKIM and DMARC. You’ll see arrow from these three items away and further into the Internet as well as back into the Microsoft 365 service. This is because these three DNS records will affect both sent and received emails and should be considered the first item on your email security check list. Some articles that may help on this include:

SPF, DKIM, DMARC and Exchange Online

Set up SPF to help prevent spoofing

Support for validation of DKIM signed messages

Use DKIM to validate outbound email sent from your custom domain

Use DMARC to validate email

When others send email to Microsoft 365, the following articles may help:

Sending mail to Microsoft 365

Services for non-customers sending mail to Microsoft 365

Inbound email is received into Microsoft 365 via Exchange Online. A component of this service is Exchange Online Protection (EOP).

Exchange Online Protection overview

EOP features

Inbound emails

The first stage of a message progressing through Exchange Online Protection is for it to traverse the Edge Protections as shown above. These are basically policies and configuration managed and maintained by Microsoft. A user is unable to alter them but information about these can be found at:

Use Directory Based Edge Blocking to reject messages sent to invalid recipients

Backscatter in EOP

How EOP validates the From address to prevent phishing

It is important to note that DNS records like SPF play an important role in helping secure email data, which is why it is important to configure them.

How Microsoft 365 uses Sender Policy Framework (SPF) to prevent spoofing

After the Edge Protection phase is complete, any inbound email is then sent to Exchange Online Protection (EOP) for further processing. It is here that there are many policies and settings that can be configured by the user. The sequence in which these take place can be found here:

Order and precedence of email protection

Generally, first to be processed is the Connection filtering.

Configure connection filtering

Then Malware filtering.

Configure anti-malware policies in EOP

Then Transport rules.

Mail flow rules (transport rules) in Exchange Online

Next are any Data Loss Prevention (DLP) policies.

Data Loss prevention

Spam filtering follows.

Anti-spam protection in EOP

Configure anti-spam policies in EOP

Anti-spam message headers in Microsoft 365

Bulk complaint level (BCL) in Exchange Online Protection EOP

Finally inbound email will be checked for phishing and spoofing.

Anti-phishing policies in Microsoft 365

Configure spoof intelligence policy

After all these the inbound email will continue to be processed by any additional protection options and features like Defender for Office 365 which will be covered in an upcoming article, so don’t think that email protection stops with EOP, it continues with Defender for Office 365 right through to the email app on the device which will all be covered in upcoming articles.

Outbound emails

If we now turn our attention to outbound emails and work from right to left, along the bottom arrow, we see that the email has a lot less policies to travel through. The main one is the Outbound spam filter.

Configure outbound spam filtering in EOP

However, it will also go through the DLP policy:

Data Loss prevention

and then Transport rules:

Mail flow rules (transport rules) in Exchange Online

You can also use

Message Encryption

if you wish to protect the contents of emails sent from Microsoft 365.

Summary

Remember, what is covered here is only the first part of the full range of protection capabilities that Microsoft 365 provides for emails. You will also see that a significant amount of these capabilities provide the ability of customisation. For the items that are user configurable in the diagram, a good rule of thumb is to implement and configure from left to right, top to bottom. Once you have all that done, then you can move onto the next stage which will be covered in the next article on this topic.

End to End email protection with Microsoft 365 – Part 2