Deployment (Part 1)

By Ashwin Venugopal -

 




To read part 2, please click here
To read part 3, please click here



Azure Resources

Microsoft Sentinel needs following resources to be created:
  1. Subscription (if a dedicated subscription(s) will be used)
  2. Resource group(s)
  3. Log Analytics workspace(s) Automation rules/playbook Alert rules
  4. Workbooks

Microsoft Sentinel offers hundreds of alert rules, workbooks, and automation playbook templates along with hunting scripts. The templates can be used to activate/deploy schedule alerts, create customized dashboards, create automation playbooks and perform threat-hunting activities. Generally, once deployed, the resources created have to be adjusted to match the existing environment, configure local credentials, etc. Methods of deployment:

  • Manual- Administrator can manually configures the Microsoft Sentinel resources with the help of Azure portal. Any manual process has the inherent risks of human operator error, lack of compliance with potential change control procedures, and undocumented changes. 

  • Automation Tools- Microsoft Sentinel resources support several infrastructure-as-code tools, such as Hashicorp Terraform, that can offer consistency to processes. One of the native Microsoft Sentinel features, allows the use of a GitHub or Azure DevOps repository to automate the deployment of detection rules, Microsoft Sentinel functions and workbooks. The repositories can be used to deploy content across multiple Microsoft Sentinel instances. 

  • Custom Scripts/Programs- Microsoft provides a PowerShell automation library called Az.SecurityInsights that can be used to script a wide range of Microsoft Sentinel-related deployment tasks. The Microsoft Sentinel community also offers additional resources like AzSentinel PowerShell library and a wide range of Azure Resource Manager (ARM) templates for various playbooks, alert rules, and workbooks. Optional Azure resources:

    • Service Principal Names (SPNs)- They are typically used in automation of playbooks for authentication while accessing various resources. They should be given minimal permissions required to perform their tasks. 
    • Storage accounts- They can be used for temporary storage of analysis data, long-term log retention, and other tasks that require basic storage outside Log Analytics.
    • Function Apps- They can perform a wide variety of tasks as serverless compute resources. However, only one type of compute platform can be used for one resource group. 
    • Key Vaults- Typically used for secure storage of secrets used by various log collectors. 
    • Event Hubs- They can be used to share analysis data in certain designs requiring integration with legacy SIEMs or third-party analytical platforms. 

However, none of the optional resources are required for the initial Microsoft Sentinel configuration.

Log Source Onboarding

Microsoft Sentinel includes many data connectors for a wide range of log sources. Hence, according to the type of log source, the onboarding process might vary from just a few clicks of the mouse, deployment of AMA, or to more complex configurations involving the deployment of additional log collection resources such as Microsoft Sentinel playbooks based on Azure Logic Apps, Azure Function Apps, and vendor-provided log retrieval tools.

Built-in Data Connectors

Microsoft Sentinel contains many connectors that can be deployed with a few clicks via Microsoft Sentinel portal and the requisite RBAC permissions. New data connectors for other products are added regularly. The built-in data connectors should be considered over the custom ones, wherever feasible, as they are fully supported by Microsoft and the Microsoft Sentinel community. 


Conclusion:

The key considerations for the deployment phase, after the completion of the high-level design, are discussed here. 





To read part 2, please click here
To read part 3, please click here

















































Comments

Post a Comment

Popular posts from this blog

Deployment (Part 3)

By Ashwin Venugopal -
Image
  To read part 1, please click  here To read part 2, please click  here Microsoft Monitoring Agent (MMA) MMA is used across multiple Microsoft solutions and has undergone a few name changes as its features and functionality have evolved. If it is being considered to be used, then following areas should be covered during a Microsoft Sentinel deployment project: Consider the timelines and the strategy for a migration to AMA (Azure Monitor Agent) before the MMA end-of-life.  Consider the central deployment and management methodology for MMA. Determine which endpoints are in scope for deployment as these affect the log ingestion volume significantly.  Azure Monitor Agent (AMA) Organizations with MMA as the main Microsoft Sentinel agent should start planning the migration to AMA as soon as possible to avoid a rushed migration. One of the main advantages of AMA is the ability to control the log collection policy centrally and apply different policies against different groups of computers, re
Read more

Project Resourcing (Part 2)

By Ashwin Venugopal -
Image
  To read part 1, please click  here Engineering - SIEM The SIEM engineers configures Microsoft Sentinel, including Log Analytics, Logic Apps, workbooks, and playbooks. They are also responsible for the following high-level tasks: Initial configuration of Azure tenant, including provisioning required resources, assigning access roles, and configuring workspace parameters like log retention, resource tagging, and blueprints.  Deployment and configuration of syslog/CEF log collection agents in appropriate locations to collect logs from on-premises devices. Generally, it will be joint effort of both system engineer and SIEM engineer, involving configuration and potential troubleshooting.  Working with system owners to enable log forwarding and configuring any required parsing of log data in Log Analytics.  Working with security operations to create and deploy KQL analytic rules to offer detections for SOC/Computer Security Incident Response Team (CSRIT) use. Tuning of alert rule parameter
Read more

Design Planning (Part 3)

By Ashwin Venugopal -
Image
  To read part 1, please click  here To read part 2, please click  here Complex Organizational Structures SIEM can be an expensive security control, hence, it is common multiple businesses to contribute to the overall expense. Various organizational units may require a level of access to specific dashboards or sets of data. Microsoft Sentinel offers the ability to assign table-level permissions and limit the level of access to the minimum required to perform requisite job functions.  Role-based Access Control (RBAC) Requirements Microsoft Sentinel offers an extensive list of Azure built-in roles that can be used to provide granular access according to the job requirements and permitted level of access. Some of them are various Microsoft Sentinel dedicated roles: Microsoft Sentinel Contributor- Can perform all engineering-related configuration, such as creating alert rules, configuring data connectors, and additional similar tasks.  Microsoft Sentinel Reader- Can query the log data stor
Read more