The Critical Role of On-Premises Monitoring In a Hybrid World

The move to the cloud has reshaped the cybersecurity landscape, shifting our focus to SaaS applications, cloud infrastructure, and the identities that access them. But for many organizations, the journey to a cloud-native world isn't complete. A vast number of businesses still rely on a hybrid environment, with on-premises infrastructure playing a foundational role. In this hybrid landscape, securing identities that span both on-premises and cloud environments is paramount.

Don't Let Your Foundation Crumble

Ignoring the security of your on-premises systems, especially your Active Directory, is a critical mistake. Attackers know this, and they're increasingly exploiting the trust relationship between on-premises and cloud identities to launch devastating attacks.

This is where a solution like Microsoft Defender for Identity becomes indispensable. It’s not just about monitoring your cloud; it’s about securing the entire identity chain, from the ground up.

The Hybrid Identity Threat: A Technical Breakdown

In a hybrid environment, your on-premises Active Directory (AD) is synchronized with Microsoft Entra ID (formerly Azure AD). This synchronization is a powerful feature, but it's also a potential attack vector. A classic attack chain often begins with the compromise of an on-premises identity, which can then be used to pivot into the cloud.

Attackers love Active Directory. It’s a treasure trove of information and a single point of control. They use a variety of techniques to gain a foothold, including:

• Credential Theft: Techniques like Pass-the-Hash and Pass-the-Ticket are used to steal authentication materials from on-premises systems.
• Reconnaissance: Attackers look for misconfigurations and weaknesses in AD to map out a path to a privileged account.
• Lateral Movement: Once an attacker has a compromised account, they use it to move stealthily through the network, escalating privileges until they can access high-value targets.

Without proper monitoring of your on-premises domain controllers, these attacks can go undetected. The attacker can perform all of their malicious activity in the "trusted" on-premises environment before making a single move into the cloud, where your cloud-native security controls are focused.

Defender for Identity: Securing Your Foundation

This is where Defender for Identity (formerly Azure Advanced Threat Protection or Azure ATP) steps in. It's a cloud-based service that acts as a specialized security camera for your on-premises Active Directory.

Here’s how it works and why it's a critical component of a modern security posture:

• Sensor Deployment: A lightweight sensor is installed directly on your on-premises domain controllers. This is a non-intrusive approach that gives the sensor access to the crucial data it needs—network traffic and event logs.
• Behavioral Analysis: The sensor doesn't just look for known malicious files. Instead, it continuously analyzes the behavior of users and entities within your on-premises environment. It uses advanced machine learning and AI to build a baseline of "normal" behavior.
• Threat Detection: When an identity-based threat occurs, Defender for Identity flags the anomalous behavior. This could be anything from a user logging in from an unusual location at an odd time, to a service account attempting to perform actions it has never performed before.
• Connecting the Dots: Defender for Identity is part of the Microsoft Defender XDR suite. This means it doesn't operate in a silo. It feeds its alerts into a unified incident timeline within the Microsoft Defender portal, where they are correlated with signals from Defender for Endpoint, Defender for Cloud Apps, and other services. This gives your security team a complete, end-to-end view of the attack, showing how a compromised on-premises identity was used to pivot to a cloud service.

The Synergistic Power of Defender for Identity and Defender for Endpoint

A common point of confusion is the difference between Defender for Identity and Defender for Endpoint. They are not competing solutions; they are complementary, working together to provide comprehensive protection.

• Defender for Endpoint is your EDR solution. It monitors the endpoints (workstations, servers) themselves for malicious activity, whether that’s a file-based attack, an unusual process, or other endpoint-level behaviors. It's your last line of defense on the device.
• Defender for Identity is your identity detection and response (IDR) solution. It watches your identity infrastructure for attacks against user accounts, whether that’s a stolen credential, privilege escalation, or lateral movement.

In a modern attack, both are crucial. A stolen credential (detected by Defender for Identity) might be used to access a workstation (monitored by Defender for Endpoint), which is then used to move laterally and compromise a cloud application (monitored by Defender for Cloud Apps). Only a unified platform like SecureSky's MXDR, which brings all these signals into a single pane of glass in Microsoft Sentinel, can provide the full picture needed to stop the attack.

In a hybrid world, you can't afford to neglect any part of your attack surface. By implementing robust monitoring of your on-premises identity infrastructure with solutions like Defender for Identity, you strengthen the foundation of your entire security posture, ensuring that the trust relationship between your on-premises and cloud environments remains a point of strength, not a point of weakness. 

Partnering for Success: How SecureSky Can Help

SecureSky is uniquely positioned to help organizations deploy and operationalize these critical security solutions. Whether you're just beginning to explore Microsoft Defender for Identity or Microsoft Defender for Endpoint, or looking to integrate it into a broader XDR strategy, our team brings deep expertise in:

• Hybrid identity and endpoint protection
• Microsoft Sentinel integration
• Continuous exposure and threat monitoring

With SecureSky’s MDR and MXDR service, you gain not only the technology but also the guidance and support needed to secure your hybrid environment—ensuring your identity infrastructure is resilient, your visibility is complete, and your response capabilities are always active.