Require multifactor authentication for elevated sign-in risk

Most users have a normal behavior that can be tracked, when they fall outside of this norm it could be risky to allow them to just sign in. You might want to block that user or maybe ask them to perform multifactor authentication to prove that they're really who they say they are.

A sign-in risk represents the probability that a given authentication request isn't the identity owner. Organizations with Microsoft Entra ID P2 licenses can create Conditional Access policies incorporating Microsoft Entra ID Protection sign-in risk detections.

The Sign-in risk-based policy protects users from registering MFA in risky sessions. If users aren't registered for MFA, their risky sign-ins are blocked, and they see an AADSTS53004 error.

User exclusions

Conditional Access policies are powerful tools, we recommend excluding the following accounts from your policies:

• Emergency access or break-glass accounts to prevent lockout due to policy misconfiguration. In the unlikely scenario all administrators are locked out, your emergency-access administrative account can be used to log in and take steps to recover access.
  • More information can be found in the article, Manage emergency access accounts in Microsoft Entra ID.
• Service accounts and Service principals, such as the Microsoft Entra Connect Sync Account. Service accounts are non-interactive accounts that aren't tied to any particular user. They're normally used by back-end services allowing programmatic access to applications, but are also used to sign in to systems for administrative purposes. Calls made by service principals won't be blocked by Conditional Access policies scoped to users. Use Conditional Access for workload identities to define policies targeting service principals.
  • If your organization has these accounts in use in scripts or code, consider replacing them with managed identities.

Template deployment

Organizations can choose to deploy this policy using the steps outlined below or using the Conditional Access templates.

Enable with Conditional Access policy

1. Sign in to the Microsoft Entra admin center as at least a Conditional Access Administrator.
2. Browse to Protection > Conditional Access.
3. Select New policy.
4. Give your policy a name. We recommend that organizations create a meaningful standard for the names of their policies.
5. Under Assignments, select Users or workload identities.
   1. Under Include, select All users.
   2. Under Exclude, select Users and groups and choose your organization's emergency access or break-glass accounts.
   3. Select Done.
6. Under Cloud apps or actions > Include, select All resources (formerly 'All cloud apps').
7. Under Conditions > Sign-in risk, set Configure to Yes.
   1. Under Select the sign-in risk level this policy will apply to, select High and Medium. This guidance is based on Microsoft recommendations and might be different for each organization
   2. Select Done.
8. Under Access controls > Grant, select Grant access.
   1. Select Require authentication strength, then select the built-in Multifactor authentication authentication strength from the list.
   2. Select Select.
9. Under Session.
   1. Select Sign-in frequency.
   2. Ensure Every time is selected.
   3. Select Select.
10. Confirm your settings and set Enable policy to Report-only.
11. Select Create to create to enable your policy.

After administrators confirm the settings using report-only mode, they can move the Enable policy toggle from Report-only to On.

Passwordless scenarios

For organizations that adopt passwordless authentication methods make the following changes:

Update your passwordless sign-in risk policy

1. Under Users:
   1. Include, select Users and groups and target your passwordless users.
2. Under Select the sign-in risk level this policy will apply to, select High.
3. Under Access controls > Block access for passwordless users.

Tip

You might need to have two policies for a period of time while deploying passwordless methods.

• One that allows self-remediation for those not using passwordless methods.
• Another that blocks passwordless users at high risk.

Remediate and unblock passwordless sign-in risk

1. Require administrator investigation and remediation of any risk.
2. Unblock the user.

Related content

• Require reauthentication every time
• Remediate risks and unblock users
• Conditional Access common policies
• User risk-based Conditional Access
• Determine effect using Conditional Access report-only mode
• Use report-only mode for Conditional Access to determine the results of new policy decisions