Conditional Access policies help defend against social engineering by enforcing strict, context-aware access controls that limit what attackers can – even if they steal valid credentials. They act as a dynamic security gate, verifying not just who is accessing a resource, but how, where, and under what conditions.

How to configure Entra Conditional Access Policies?

1.Require Multi-Factor Authentication (MFA)

Even if a user is tricked into giving up their password (via phishing or pretexting), CA can require MFA before granting access.

This blocks attackers who don’t have the second factor (e.g. phone, app, hardware token).

2.Block Access from Risky Locations or Devices

CA can deny access from:

• Unfamiliar IP addresses
• Untrusted countries
• Unmanaged or jailbroken devices

This stops attackers who try to log in from outside the organization’s normal geography or device fleet.

3.Use Risk-Based Signals

CA integrates with Microsoft Entra Identity Protection to assess:

• Sign-in risk (e.g., impossible travel, leaked credentials)
• User risk (e.g., account flagged for compromise)

Access can be blocked or require reauthentication based on these signals.

Best Practices

• Enable MFA for all users, especially admins
• Block legacy authentication (which bypasses MFA)
• Use named locations and trusted IPs
• Monitor risky sign-ins and automate responses
• Test policies with report-only mode before enforcing

Real-World Example

Imagine an attacker tricks an employee into revealing their Microsoft 365 credentials. With Conditional Access:

• The attacker’s login from an unknown IP triggers a high sign-in risk
• Access is blocked or challenged with MFA
• Even if MFA is bypassed, access to sensitive apps is restricted to compliant devices only
• The attack is contained and logged, giving security teams time to respond