Common Conditional Access policy: Sign-in risk-based multifactor authentication

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 tenant-wide account lockout. In the unlikely scenario all administrators are locked out of your tenant, your emergency-access administrative account can be used to log into the tenant to take steps to recover access.
  • 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. Service accounts like these should be excluded since MFA can't be completed programmatically. 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. As a temporary workaround, you can exclude these specific accounts from the baseline policy.

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 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.
    1. Select Grant access, Require multifactor authentication.
    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.