Control: 1.1.4 Ensure multifactor authentication is enabled for all users

Description

Enable multifactor authentication for all users in the Microsoft 365 tenant. Users will be prompted to authenticate with a second factor upon logging in to Microsoft 365 services. The second factor is most commonly a text message to a registered mobile phone number where they type in an authorization code, or with a mobile application like Microsoft Authenticator.

Multifactor authentication requires an individual to present a minimum of two separate forms of authentication before access is granted. Multifactor authentication provides additional assurance that the individual attempting to gain access is who they claim to be. With multifactor authentication, an attacker would need to compromise at least two different authentication mechanisms, increasing the difficulty of compromise and thus reducing the risk.

Remediation

To enable multifactor authentication for all users:

1. Navigate to the Microsoft Entra admin center https://entra.microsoft.com.
2. Click expand Azure Active Directory > Applications select Enterprise Applications.
3. Under Security, select Conditional Access.
4. Click New policy.
5. Go to Assignments > Users and groups > Include > select All users (and do not exclude any user).
6. Select Cloud apps or actions > All cloud apps (and don't exclude any apps).
7. Access Controls > Grant > Require multi-factor authentication (and nothing else).
8. Leave all other conditions blank.
9. Make sure the policy is Enabled/On.
10. Create.

Default Value: Disabled.