The castle-and-moat network perimeter is dead. If a threat actor breaches your VPN, and your internal network is flat, it's game over. Ransomware groups rely on this lateral movement. Zero Trust assumes breach and verifies explicitly at every transaction.
The Microsoft Zero Trust Stack
While many vendors sell "Zero Trust" in a box, we prefer implementing it natively for enterprises already heavily invested in Microsoft 365. Here is our exact blueprint.
1. Identity as the New Perimeter (Azure AD / Entra ID)
We mandate Conditional Access Policies. MFA is no longer binary. We evaluate the context of the authentication request:
- User Risk: Is the user's password in a known breach? (Identity Protection).
- Sign-in Risk: Is this an impossible travel scenario?
- Device State: Is the device compliant in Intune? Does it have the latest OS patches?
If the device isn't compliant, access to SharePoint/Exchange is blocked, regardless of whether they have the right password and MFA token.
2. Least Privilege with PIM
No one should have standing Global Admin privileges. We deploy Privileged Identity Management (PIM). Admins must request elevation just-in-time (JIT), provide a ticket number as justification, and the access automatically expires after 2 hours.
3. Micro-segmentation
We deploy Defender for Endpoint across all servers and endpoints, combined with network security groups (NSGs) in Azure. If an endpoint is compromised, Defender automatically isolates the machine from the network, preventing lateral ransomware spread.