Why is everyone so excited about the new #azuread Authentication Strength feature in Conditional Access that was announced at Ignite last month?
Here's are short thread about the feature.
PS. There is a bonus if you read all the way to the end 😉👇
This illustration from @Yubico shows that not all MFA is of equal strength when protecting your users. Some like Phone number and email are very weak compared to others.
That's all well and good but moving our users off Voice/SMS is going to take some time.
Now this is where Authentication Strength comes into play. Before this feature was released, the only way to remove phone MFA was to turn it off at the tenant level at adlegacymfa.cmd.ms
As you can imagine it's going to be total chaos if you unchecked the Phone and SMS options for all your users.
Instead what you really want is to gradually improve the auth strength in your org.
An ideal place to start could be to remove Phone/SMS for privileged admin users.
Applying Auth Strengths is a two step process.
#1 Decide/ define the Authentication Strength
You can use one of the built-in strengths or create your own.
Here I'm following NIST guidelines and creating a custom auth strength that excludes SMS & Voice.
#2 Enforce the Auth Strength using a Conditional Policy
Next we head over to adca.cmd.ms and define a CA policy that requires this new auth strength.
Since this is in CA you get to use all the various filters to scope the where and when this strength is enforced.
All set!
Now the most important part. What is the user's experience?
If their original MFA doesn't meet the requirement the user is prompted with a step up experience to the stronger auth.
For this user we applied a policy that excluded Voice.
So your Microsoft 365 tenant has been compromised by a malicious app!
Here's a step by step guide to block access to the app and remove it from your tenant -Bkmk this!
1️⃣ Go to Microsoft Entra → Enterprise Apps
2️⃣ Select the compromised app
3️⃣ Permissions → Review Permissions
Select 'This app is malicious and I'm compromised'
Follow the recommendations to
✅ Disable the app
Then run the PowerShell scripts that is generated to
✅ Require user assignment
✅ Revoke all permissions
✅ Invalidate refresh tokens of users with access to the app
What are HAR files?
A HAR file is a recording of your current session & includes all web traffic including secrets & tokens.
Admins usually share these files with customer support when troubleshooting issues.
Here's a thread on how you can handle .har files safely.
🧵⬇️
Exporting HAR files
There are a few ways to record your session to create HAR files. You might need to use different tools depending on what you are recording.
→ Browser
Every modern browser lets you export an HAR file of the current tab's session from the Network tab.
→ Desktop
Sometimes you might need to troubleshoot a non-browser-based app, for example a desktop app like Outlook or a CLI or PowerShell script.
Your admins are usually asked to use an app like Fiddler that adds a system proxy to capture all the web traffic on the desktop.
How many of your users have access to your customer's credit card data❓️
Why not apply the forced expiry to the subset of users that actually handle credit card data?