Boost security of your remote workers with confidence using Security Policy AdvisorJuly 29, 2020
When it comes to securing the Microsoft 365 Apps using policies, IT Pros often face a challenge: You want to tighten security as much as possible to keep the bad guys out, but at the same time you do not want to impact your user’s productivity. And you would like to be able to evaluate the potential impact of a security config change before fully enforcing it. Sounds familiar? Then this blog post is for you!
This post will show you how to leverage the Security Policy Advisor (SPA) to identify slack in your security configuration, make changes to your policy settings and validate the new config first before enforcing them, reducing the risk to impact user productivity. The data-driven service allows you to make decisions based on facts like actual feature usage or if your users are already under attack by e.g. malicious Office documents being sent to them, rather than just guessing what the impact of a change might be.
With more people working from home, traditional security layers like working on a trusted network or trusted device are going away. It becomes more important to meet the user where they are and providing a secure setup without affecting their productivity. The Security Policy Advisor (SPA) is a service hosted in your tenant, so you can put it to work within minutes. No need for any on-prem infrastructure.
SPA uses the Office cloud policy service (OCPS) to enforce security policies in the Office applications. Such policies are bound to the AzureAD user identity, independent from the actual device used or how this device is managed (if at all). When a user signs into an Office application using their work credentials, SPA and OCPS will ensure that the policies are applied, at home or at work, on corporate and personal devices.
SPA currently supports several security policies, but in the following article we will focus on one policy which can drastically reduce your exposure to attacks targeting Office: VBA Macro Notification Settings. If you are an Office Desktop Admin, it is likely that you have had to deal with this dilemma: Restrict macro execution to protect your users and enterprise from malware attacks like this one or leave it enabled so you don’t risk impacting users productivity? Sounds familiar? OK, let's look at an example on how you could tackle this challenge.
Step 1 – Review requirements and create policy configurations
There are only two requirements for using Security Policy Advisor:
- Devices must run at least version 1908 of Microsoft 365 Apps for enterprise.
- Apps must be allowed to send required service data for Office.
Use the Office cloud policy service (OCPS) to create a policy configuration. You are not required to configure any policies in this configuration to receive recommendations. Have a look at our OCPS walkthrough guide for further guidance on using OCPS.
Step 2 – Enable Security Policy Advisor
Next step is to enable SPA. Navigate to config.office.com, sign in with Global Administrator, Security Administrator, or Office Apps Admin permissions and click on Security. Toggle the switch to On.
That’s it. If you have policy configurations created in OCPS, SPA will now start generating recommendations for those. This happens quickly, typically within minutes. You can also create a policy configuration from Security Policy Advisor using the Create a policy configuration button.
Step 3 – Review recommendations and tighten up security
Once Security Policy Advisor has finished analyzing data, it will inform you of new recommendations. You can click through the policies and see a full list of settings to consider:
For each policy you can review more details by clicking on it. It will give you more information on how many users have actually used the feature and for specific settings (macros) also data on any attacks through this vector targeted at users in the group. Here’s an example of how the data might look like for the VBA Macro Notification Settings policy recommendation.
So in this case, you can see that no user has actually opened Excel documents with macros (Total users), but all users have been targeted by malicious macros. So there is a big opportunity to boost security without impacting the user’s productivity. SPA provides you the information you need to justify this change and take it through a change management process.
That’s one of two features which give you confidence when using SPA: You will get historical data based on the actual usage of the Office apps as well as any attacks detected by Office 365 Advanced Threat Protection (ATP). No more guessing if a certain user group is actually using a feature and is at risk by not restricting it. You get actionable data and should act on it.
Perhaps you still have reservation acting on these recommendations and data. This is where the second feature comes in handy: You can set a policy, but allow the user to override it. The above example strongly suggests to disable VBA notifications as users are not using this feature and are under attack. But we might want to flight this new setting to users first and monitor impact.
So in this example you would review the data for each of the VBA Notifications settings (there is one per application), accept the recommendation to disable VBA macros, but set Override to Enabled.
After clicking Apply, the new policy is set and will disable VBA macros for all targeted users. In case a user opens a document with macros embedded, a notification is shown that the VBA macro was disabled. In addition, the user is given an option to override this policy and still enable macros. When they do, this information is captured and surfaced back to you in the admin portal.
This approach combines the power of having insights into historical data, but also safely try out a more restrictive security configuration.
Step 4 – Monitor productivity impact and adjust configuration
After a given time, e.g. two weeks, you can review how often users have actually used the option to override the setting. Log into the SPA UI, select the policy and switch to the Applied policies tab. Clicking on the individual setting will bring up the policy details and you can review how many users have overridden the setting.
In the above example, you could go forward with confidence and disable the override to boost overall app security. You first must roll back the policy, select the policy from the recommendations tab again and re-deploy with user override disabled.
In case users opted to override the setting, you might want to move these users to another Azure AD security group and targeted them with a less strict security configuration using OCPS.
Step 5 – Iterate
A common statement in IT security is “Security is not a one-time activity, it is a process” and this is also true when it comes to securing Office applications. After deploying the VBA notification setting, you should start looking at the other available policies like:
- Block macros in Office files from the internet
- Disable All ActiveX
- Check ActiveX objects
- Blocking legacy file formats
We recommend that you first check if there are any recorded attack attempts for the Block macros in Office files from the internet settings. If yes, you might want to focus on these first to quickly reduce your attack surface. Then work your way through the list over time. This will boost your security stance step-by-step by removing any slack. Revisit the dashboard on a regular base to monitor impact and adjust policies where needed.
By default, we will show recommendations with a low productivity impact first. You can switch the Show all recommendations toggle to get a full view:
It is key to find the right balance between being restrictive and still allowing people to do their job. If security is too restrictive, users often start to work around these limitations and this might be a greater impact to your security posture then having a configuration which is not cranked up to the maximum.
About the Authors
For this blog post the Microsoft 365 Apps Ranger Team at Microsoft partnered with the engineering team behind Security Policy Advisor. Feel free to share your questions in the comment section. For feedback on SPA, please use the feedback functionality in the config.office.com portal, it will get routed directly to the SPA team.
Q: SPA is not generating any recommendations, what could be wrong?
A: Double check if required diagnostic data is enabled in your environment and devices can upload the data to the required endpoints.
Q: Required diagnostic data is enabled, still nothing. What else could be the cause be?
A: SPA needs a certain share of users to report data back to generate recommendations per group. Double-check if most users in a targeted group are active Microsoft 365 Apps users and have diagnostic data enabled.