01
What Hybrid Infrastructure Means in 2026
Hybrid infrastructure means different things to different businesses. For some, it means running Active Directory on-premise while using Microsoft 365 and Azure in the cloud. For others, it means production workloads split across on-premise servers and AWS or Azure.
What all hybrid environments share is complexity: multiple identity stores, multiple network boundaries, multiple monitoring panes, and the challenge of applying consistent security policies across environments that were designed independently.
The number one hybrid infrastructure risk is identity sprawl — on-premise accounts that aren't synchronised, cloud accounts that don't enforce the same policies, and service accounts with no oversight.
02
Identity: Bridging On-Premise and Cloud
Azure AD Connect / Entra Connect Sync
✓Synchronise on-premise Active Directory users to Entra ID
✓Password Hash Synchronisation (PHS) — recommended for most SMBs: passwords sync to cloud, MFA enforced via Conditional Access
✓Pass-Through Authentication (PTA) — authentication validated against on-premise AD
✓Seamless Single Sign-On — users logged into domain-joined PCs get SSO to Microsoft 365 without re-prompting
Hybrid identity security
✓Entra ID Identity Protection applies to synchronised users — risk-based Conditional Access works for hybrid identities
✓Monitor sync health via Entra Connect Health — alerts when sync fails
✓On-premise password policy should match or exceed cloud policy — weak on-premise passwords carry into the cloud
✓Retire on-premise accounts promptly when staff leave — they'll otherwise remain active in Entra ID
03
Secure Network Connectivity
Site-to-Site VPN
✓Connects on-premise network to Azure VNet or AWS VPC via encrypted tunnel
✓Appropriate for: regular data transfer between on-premise and cloud workloads
✓Key considerations: redundant tunnels for HA, bandwidth capacity planning, routing design
Azure ExpressRoute / AWS Direct Connect
✓Dedicated private circuit from on-premise to cloud provider — not over the public internet
✓Appropriate for: high-bandwidth requirements, latency-sensitive workloads, regulated data that cannot traverse public internet
✓More expensive than VPN — typically used for larger workloads or compliance requirements
Zero Trust Network Access (ZTNA)
✓Replace VPN for remote user access — ZTNA grants access to specific applications, not the entire network
✓Microsoft Entra Private Access — ZTNA for on-premise applications, without requiring VPN
✓Eliminates lateral movement risk if a remote user's device is compromised
04
Unified Security Monitoring
The most common hybrid monitoring gap: on-premise events are visible in SIEM, cloud events are not — or vice versa. Effective hybrid monitoring requires all event sources flowing to a single SIEM.
Microsoft Sentinel data connectors
✓Microsoft 365 and Entra ID — natively connected
✓Azure resources — via Azure Monitor / Diagnostic Settings
✓On-premise Windows servers — via Azure Monitor Agent (AMA)
✓On-premise Linux servers — via AMA or Syslog
✓Network devices (firewalls, switches) — via Syslog or CEF connector
✓Third-party cloud (AWS) — via Amazon Web Services connector in Sentinel
Sentinel ingesting on-premise Windows event logs via Azure Monitor Agent gives you hybrid SIEM coverage without deploying separate on-premise SIEM infrastructure.
05
Patch Management Across Environments
Consistent patch management is one of the hardest operational challenges in hybrid environments. On-premise systems may use WSUS or SCCM. Cloud VMs may use Azure Update Manager or AWS Systems Manager. The risk: gaps where neither system is covering certain machines.
✓Azure Update Manager — unified patch management for Azure VMs and on-premise servers via Azure Arc
✓AWS Systems Manager Patch Manager — for EC2 instances and on-premise servers registered via Systems Manager Agent
✓Intune — for workstations (Windows, macOS) regardless of network location
✓Monthly patch cadence minimum — emergency patches for critical vulnerabilities within 48–72 hours
✓Patch compliance reporting — unified view of all systems and their patch status
Azure Arc
Azure Arc extends Azure management capabilities to on-premise servers — enabling Azure Policy, Defender for Cloud, Update Manager, and Sentinel connectivity for servers not in Azure. This is the recommended approach for hybrid management in a Microsoft-centric environment.
06
De4sec Hybrid Infrastructure Service
Architecture Assessment
Review current hybrid topology. Identify identity gaps, network security weaknesses, and monitoring blind spots.
Identity Unification
Entra Connect Sync deployment, Conditional Access for hybrid identities, Entra Private Access for remote access.
Network Security
Site-to-site VPN or ExpressRoute configuration, network segmentation design, ZTNA implementation.
Unified SIEM
Microsoft Sentinel deployment with on-premise and cloud data connectors — single monitoring pane for hybrid environment.
