Email overrides are not best practice

I see a lot of email configurations in Microsoft 365 that use some form of override to ‘get around’ a delivery issue. Doing so is simply not best practice and in fact opens you up for additional attacks.

For more information, let’s review the Microsoft document:

Create safe sender lists in EOP

which says:

  • We don’t recommend managing false positives by using safe sender lists, because exceptions to spam filtering can open your organization to spoofing and other attacks.
  • Use Outlook safe senders – This method creates a high risk of attackers successfully delivering email to the Inbox that would otherwise be filtered; however, the user’s Safe Senders or Safe Domains lists don’t prevent malware or high confidence phishing messages from being filtered.
  • Use the IP allow lists – Without additional verification like mail flow rules, email from sources in the IP Allow List skips spam filtering and sender authentication (SPF, DKIM, DMARC) checks. This creates a high risk of attackers successfully delivering email to the Inbox that would otherwise be filtered; however, the IP Allow List doesn’t prevent malware or high confidence phishing messages from being filtered.
  • Use allowed sender lists or allowed domain lists – This method creates a high risk of attackers successfully delivering email to the Inbox that would otherwise be filtered; however, the allowed senders or allowed domains lists don’t prevent malware or high confidence phishing messages from being filtered. Do not use domains you own (also known as accepted domains) or popular domains (for example, microsoft.com) in allowed domain lists.

In short, if you are using white lists or the like you are creating a vulnerability in your environment that attackers can exploit. All inbound messages should be filtered through appropriately configured mail filtering policies. If you want information on setting these appropriately see:

Mail flow best practices for Exchange Online and Office 365

Best practices for configuring standalone EOP

Recommended settings for EOP and Defender for Office 365 security

To get an overall picture of all the message overrides in your environment visit the Security and Compliance admin portal:

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Locate the Reports option on the left and then select Dashboard as shown, from the expanded options. Then on the right locate the Threat protection status tile as shown and select it.

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From the pull down options in the top right, as shown above, select Message override.

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You should now see a nice summary of any messages passing through your environment that are overriding your configurations. Don’t forget that you can also View details table and select to Filter in the top right of this report.

A direct link to this report can be found here:

Threat Protection status – Message override

Overriding policies conditions is something that should be avoided as much as possible, simply because it increases the risk in your environment. Also, if you haven’t already, go take a look at what messages are overriding in your environment today and try to eliminate these to improve your security.

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:

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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.

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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


CIAOPS Need to Know Microsoft 365 Webinar–January

laptop-eyes-technology-computer

We’re back for 2021 and for January we are going to cover a topic which remains a mystery to many – PowerShell. I’ll show you how to quickly set up PowerShell to use with Microsoft 365 and some handy things that you can do with it to make your life easy through automation. I’ll also have the latest news from Microsoft and as always there will be time for your questions.

You can register for the regular monthly webinar here:

January Webinar Registrations

The details are:

CIAOPS Need to Know Webinar – January 2021
Friday 29th of January 2021
11.00am – 12.00am Sydney Time

All sessions are recorded and posted to the CIAOPS Academy.

The CIAOPS Need to Know Webinars are free to attend but if you want to receive the recording of the session you need to sign up as a CIAOPS patron which you can do here:

http://www.ciaopspatron.com

or purchase them individually at:

http://www.ciaopsacademy.com/

Also feel free at any stage to email me directly via director@ciaops.com with your webinar topic suggestions.

I’d also appreciate you sharing information about this webinar with anyone you feel may benefit from the session and I look forward to seeing you there.

Enabling Play my emails on iOS

Play your emails on iOS has been with us for a while now. My experience is however that most documentation doesn’t tell you how to actually enable this if it is not already on.

To do so, ensure you have a Bluetooth connection to your iOS device. That could be a wireless headset or in your car.

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Click the icon in the very top right of you Outlook app once it is open as shown above.

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That should display the ‘back stage’ as shown above. Select the Play button on the left hand side towards the bottom as shown.

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If the setting is Off then switch it On.

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You can now make any adjustments to your configuration.

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If you return to ‘back stage’ of the app and press the same Play button Cortana will appear and you’ll be able to have your emails read to you.

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You can get back to the Play My Email configuration at anytime now via the app settings as shown above.

For more details on Play My Email in Outlook see:

Recovering a Deleted Stand Alone SharePoint site

Recovering a deleted stand alone SharePoint using the admin center is quick and easy. You’ll be able to do for up to 93 days after you delete the site. If you do delete a SharePoint site using the admin center be careful that it isn’t connected to other shared resources like Microsoft Teams. if it is, then use the recommended process for removing the whole Microsoft Team not just the SharePoint.

The above will will show the process of identifying a stand alone SharePoint site, the various ways that you can delete it using the web interface and the how to restore it. Remember, you have up to 93 days to do this if you need to but you can also immediately purge the site if you need to reclaim storage space as well. It is all pretty simple and the video will run you through that process.

Using a Microsoft Template for a new SharePoint Online site

It is now super  easy to add a really classy template to your SharePoint Site Collection, to make creating a high impact and engaging site really easy. All you need to do is firstly login to your Microsoft 365 environment as a global administrator and then visit:

https://lookbook.microsoft.com

Next, just select the template that you like and press the button to add it to your tenant. In less than five minutes you’ll have a stunning starting point for your collaboration site.

If you want to see that in action just watch the above video.