Optimizing Microsoft Defender for Identity for Advanced Identity Protection

Understanding Microsoft Defender for Identity

Microsoft Defender for Identity, formerly known as Azure Advanced Threat Protection (Azure ATP), is a cloud-based security solution that leverages on-premises Active Directory signals to identify, detect, and investigate advanced threats, compromised identities, and malicious insider actions targeting your organization. This powerful tool provides security professionals and SecOps analysts with the insights and tools they need to proactively protect their hybrid environments.

At the core of Defender for Identity is its ability to monitor user activities and behaviors, detect anomalies, and alert on potential security threats. By analyzing a wide range of data sources, including Active Directory logs, Kerberos authentication, and NTLM events, Defender for Identity builds a comprehensive profile of user identities and activities within the organization. This enables the solution to identify suspicious patterns, such as lateral movement, credential theft, and privilege abuse, that could indicate a security breach.

One of the key benefits of Defender for Identity is its integration with other Microsoft security solutions, such as Microsoft Defender for Endpoint and Microsoft Defender for Office 365. By correlating signals from these different sources, Defender for Identity can provide a more holistic view of the threat landscape, enabling security teams to respond more effectively to complex, multi-stage attacks.

Deploying Microsoft Defender for Identity

Deploying Defender for Identity involves several steps, each of which is crucial to ensuring a successful implementation. Let’s explore the key deployment requirements and considerations:

Licensing and Tenant Setup

To deploy Defender for Identity, you’ll need one of the following Microsoft 365 licenses:
* Microsoft 365 F1/F3 or Office 365 F3 with Enterprise Mobility + Security E3
* Enterprise Mobility + Security E5
* Microsoft 365 E3/A3/G3
* Microsoft 365 E5/A5/G5

During the deployment process, you’ll need to create a Defender for Identity workspace within your Microsoft Entra (formerly Azure Active Directory) tenant. This requires having at least one Security Administrator role assigned to your account.

Directory Service Account Configuration

Defender for Identity requires at least one Directory Service account with read access to all objects in the monitored domains. This account is used by the Defender for Identity sensors to communicate with the cloud service and gather the necessary data for threat detection and investigation.

It’s recommended to use a dedicated service account for this purpose, rather than a user account, to ensure the necessary permissions are in place and to maintain a clear separation of responsibilities.

Sensor Installation and Configuration

The Defender for Identity sensor is the on-premises component that collects and forwards data to the Defender for Identity cloud service. The sensor can be installed on the following operating systems:

• Windows Server 2019
• Windows Server 2016
• Windows Server 2012 R2 (extended support ends in October 2023)
• Windows Server 2012 (extended support ends in October 2023)

When installing the sensor, you’ll need to provide the access key generated during the Defender for Identity workspace creation. This key allows the sensor to securely connect to the cloud service.

It’s important to ensure that the domain controllers, AD FS, AD CS, and Entra Connect servers where the Defender for Identity sensor is installed have the necessary resources and network connectivity. The table below outlines the recommended hardware specifications and network requirements:

Packets per Second, CPU, and Memory Requirements

This includes physical cores, not hyper-threaded cores.
*Random-access memory (RAM)

It’s also essential to ensure that the time on all servers and domain controllers is synchronized within five minutes of each other. This is necessary for Defender for Identity to accurately analyze and correlate events.

Sensor Deployment and Validation

To deploy the Defender for Identity sensor, follow these steps:

1. Sign in to the Defender for Identity portal (https://portal.atp.azure.com) using the Azure account with the Security Administrator role.
2. Navigate to the “Configuration” section and copy the access key.
3. Install the Defender for Identity sensor on the target server, entering the access key and installation path.
4. Once the installation is complete, reboot the server.
5. After the initial deployment, wait at least 15 minutes for the backend services to fully initialize.
6. Sign in to the Defender for Identity portal and verify that the sensor is connected and reporting data.

If you encounter any issues during the deployment process, refer to the troubleshooting section later in this article.

Optimizing Defender for Identity for Advanced Identity Protection

Now that you have a basic understanding of the Defender for Identity deployment process, let’s explore ways to optimize the solution for advanced identity protection:

Configuring Honeytoken Accounts

Honeytoken accounts are a powerful feature in Defender for Identity that can help detect and alert on suspicious activities. These are typically dormant accounts that are used as traps for malicious actors. Any authentication or activity associated with these honeytoken accounts triggers an alert, indicating a potential security breach.

To configure honeytoken accounts, follow these steps:

1. Identify accounts that are not actively used within your organization.
2. Designate these accounts as honeytoken accounts in the Defender for Identity portal.
3. Monitor the portal for any alerts related to the honeytoken accounts, as these could indicate unauthorized access attempts or lateral movement.

Monitoring Sensitive Accounts and Groups

In addition to honeytoken accounts, it’s crucial to monitor sensitive accounts and groups within your organization. These are typically high-privilege accounts or groups that, if compromised, could lead to a significant security breach.

To configure the monitoring of sensitive accounts and groups:

1. Identify the critical accounts and groups that you want to monitor, such as domain administrators, service accounts, and sensitive security groups.
2. Add these accounts and groups to the “Sensitive Accounts” and “Sensitive Groups” sections in the Defender for Identity portal.
3. Defender for Identity will then closely monitor any activities or changes related to these sensitive entities, alerting you to potential threats.

Enabling Detailed Auditing Policies

Defender for Identity relies on specific Windows Event log entries to enhance its detection capabilities and provide additional context on user activities. To ensure that Defender for Identity can effectively monitor your environment, you should enable the following audit policies:

You can configure these audit policies using a dedicated Group Policy Object (GPO) or the Default Domain Controllers Policy.

Additionally, you should enable the following network security settings:

• Network security: Restrict NTLM: Outgoing NTLM traffic to remote servers – Audit all
• Network security: Restrict NTLM: Audit NTLM authentication in this domain – Enable all
• Network security: Restrict NTLM: Audit Incoming NTLM Traffic – Enable all

These settings will ensure that Defender for Identity can effectively monitor and analyze NTLM-related activities, which are often associated with lateral movement and credential theft attacks.

Enabling SAM-R Enumeration

To build accurate lateral movement paths and provide comprehensive threat detection, Defender for Identity requires the ability to perform SAM-R (Security Account Manager Remote) enumeration. This allows the solution to gather information about user accounts and their privileges within the environment.

To enable SAM-R enumeration for Defender for Identity, you’ll need to edit the SAM policy. This can be done by creating a dedicated GPO or modifying the Default Domain Controllers Policy.

Integrating with Other Microsoft Security Solutions

Defender for Identity is designed to work seamlessly with other Microsoft security solutions, such as Microsoft Defender for Endpoint and Microsoft Defender for Office 365. By integrating these tools, you can benefit from a more comprehensive and coordinated approach to identity and threat protection.

For example, by integrating Defender for Identity with Defender for Endpoint, you can correlate user activities and device-level events to gain a deeper understanding of potential security threats. This can help you identify and respond to advanced attacks that leverage both user credentials and compromised devices.

Similarly, integrating Defender for Identity with Defender for Office 365 can provide insights into suspicious email activities, such as credential phishing attempts or unauthorized access to sensitive information. This can help you detect and mitigate threats that target user identities and sensitive data within the Microsoft 365 ecosystem.

Monitoring and Troubleshooting Defender for Identity

Effective monitoring and troubleshooting are crucial for ensuring the ongoing success of your Defender for Identity deployment. Let’s explore some key considerations and best practices in this area:

Monitoring Defender for Identity Alerts and Incidents

The Defender for Identity portal provides a centralized interface for monitoring and investigating security alerts and incidents. Security professionals and SecOps analysts can use this portal to:

• Review and triage alerts generated by Defender for Identity’s detection capabilities
• Investigate the root causes of security incidents
• Gather evidence and forensic data to support incident response and remediation efforts

By regularly reviewing the alerts and incidents within the Defender for Identity portal, you can stay informed about potential security threats and take appropriate actions to mitigate them.

Troubleshooting Deployment and Connectivity Issues

During the deployment and ongoing operation of Defender for Identity, you may encounter various issues, such as sensor connectivity problems or configuration errors. Here are some common troubleshooting steps to address these challenges:

1. Sensor Connectivity Issues:
2. Ensure that the sensor can communicate with the Defender for Identity cloud service using the appropriate network configuration (direct internet, proxy, or ExpressRoute).
3. Check for any firewall or network policies that may be blocking the necessary ports and protocols.
4. Verify that the sensor has the correct access key and is properly configured.

5. Reboot the sensor server to restart the necessary services.

6. Sensor Installation Errors:

7. Verify that the target server meets the minimum hardware requirements for the expected traffic volume.
8. Ensure that the server is not running in a Multi Processor Group mode, which is not supported for Windows Server 2008 R2 and 2012.
9. Install the Npcap driver with the WinPcap mode, as required for NIC Teaming on the sensor server.

10. Check for any conflicting software or drivers that may be interfering with the sensor installation.

11. Logging and Troubleshooting:

12. Review the Defender for Identity deployment logs, which are located in the C:\Users\Administrator\AppData\Local\Temp directory (or one directory above %temp%).
13. Check the sensor logs in C:\Program Files\Azure Advanced Threat Protection Sensor\<version number>\Logs.
14. If you encounter any errors or issues that you cannot resolve, consult the Defender for Identity documentation or reach out to Microsoft Support for further assistance.

By proactively monitoring your Defender for Identity deployment and addressing any issues that arise, you can ensure that the solution continues to provide advanced identity protection and threat detection for your organization.

Conclusion

Microsoft Defender for Identity is a powerful cloud-based security solution that can significantly enhance the protection of your hybrid environment. By understanding the deployment requirements, optimizing the configuration for advanced identity protection, and implementing effective monitoring and troubleshooting practices, you can leverage Defender for Identity to detect and respond to a wide range of security threats targeting your organization’s user identities and privileged accounts.

Remember, the key to success with Defender for Identity is a comprehensive, multi-layered approach to identity and access management, coupled with a deep understanding of your organization’s unique security needs and threat landscape. By staying vigilant and continuously improving your Defender for Identity deployment, you can safeguard your business against the ever-evolving landscape of cyber threats.

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