Create and customize alert rules in Microsoft Sentinel

Microsoft Sentinel is a cloud-native Security Information and Event Management (SIEM) solution that provides intelligent security analytics and threat intelligence across the enterprise. A crucial functionality of Microsoft Sentinel is its capability to create and customize alert rules to identify specific events or behaviors that indicate potential security risks. On passing the ‘AZ-500 Microsoft Azure Security Technologies’ exam, you will have to be adept at navigating this capability.

Understanding Alert Rules in Microsoft Sentinel

An alert rule in Microsoft Sentinel is designed to detect potentially harmful activities within your data. It works by running queries across your collected data at a frequency that you set, such as every 5 minutes, hourly, or daily. These queries are designed to look for specific activities or trends that may indicate a threat.

These alerts can be customized according to specific security needs. The effectiveness of these alerts, therefore, depends upon accurately defining the search query, frequency, incident settings, and automated responses that meet your organization’s needs.

Creating Alert Rules

Creating an alert rule involves writing a particular Kusto Query Language (KQL) query that the alert rule will run in the data at set intervals. Let’s look at an example of how to create a simple alert rule.

• Step1: In the Microsoft Sentinel dashboard, in the ‘Configuration’ section, click on ‘Analytics’.
• Step2: To create a new rule, click on ‘+ Create’ and then select ‘Scheduled alert rule’.
• Step3: Fill in the required details, like rule details (name, description, severity, etc.), rule logic (set up your query, rule period and frequency), and incident settings.

The query could look something like this:

SigninLogs
| where TimeGenerated > ago(1d)
| where ResultType !in ("0","50058","50144","50148","50140","50126","50143")

This example query triggers an alert when there have been any non-successful sign-in attempts in the last day.

Customizing Alert Rules

One of the significant benefits of using Microsoft Sentinel for your security needs is the power to customize your alert rules. You can modify the existing rules to better align with your organization’s requirements or create entirely new ones.

For instance, you can increase or decrease the frequency of the alert rule according to the severity or need of the specific monitoring. Similarly, you can customize the alert rule query to focus on a particular type of data or event.

Responding to Alerts

Once an alert is triggered, Microsoft Sentinel allows you to act on it manually using the ‘Incident’ pane or automate a response using Playbooks.

Playbooks are collections of procedures that can be run from Microsoft Sentinel in response to an alert. These automation scripts can help you save time when dealing with common or expected incidents.

Summing Up

Security is paramount in every organization, and the mastery of Microsoft Sentinel alert rules is an essential component for Azure security professionals planning to pass the exam ‘AZ-500 Microsoft Azure Security Technologies’. The powerful and flexible alert system of Microsoft Sentinel ensures that security professionals are always ready to tackle threats and guard their infrastructure.

Remember, the key to using alert rules in Microsoft Sentinel effectively lies with understanding the type of data you are collecting, understanding what you consider being a security risk, and being able to express that risk in a KQL query. If these tasks are handled correctly, you are better equipped to fend off security risks and troubleshoot issues.

Practice Test

True or False: Microsoft Sentinel allows users to create and customize alert rules based on their security needs.

• True
• False

Answer: True.

Explanation: Microsoft Sentinel is designed to enhance security management capabilities by allowing users to create and customize alert rules based on their specific security requirements.

Multiple Choice: Which of the following can be used to create alert rules in Microsoft Sentinel?

• a) Kusto Query Language (KQL)
• b) JavaScript
• c) Python
• d) Swift

Answer: a) Kusto Query Language (KQL)

Explanation: Microsoft Sentinel utilizes KQL (Kusto Query Language) to create alert rules.

True or False: Once an alert rule is created in Microsoft Sentinel, it cannot be modified or deleted.

• True
• False

Answer: False.

Explanation: Microsoft Sentinel allows users to modify and delete alert rules as needed, thus providing flexibility and effective security management.

Multiple Choice: How can you validate that an alert rule is correctly set up in Microsoft Sentinel?

• a) Manually trigger the alert
• b) Wait for a security issue to occur

Answer: a) Manually trigger the alert

Explanation: To ensure that an alert rule is correctly set up, it is best to manually trigger the alert. Waiting for a security issue to occur is not a reliable approach.

True or False: Microsoft Sentinel alert rules can be based on both behavioural analytics and threat intelligence.

• True
• False

Answer: True.

Explanation: Microsoft Sentinel provides users with the capability to create alert rules based on both behavioural analytics and threat intelligence.

Multiple Choice: How many severity levels exist for alert rules in Microsoft Sentinel?

• a) 2
• b) 3
• c) 4
• d) 5

Answer: c) 4

Explanation: Microsoft Sentinel provides four severity levels for alert rules: High, Medium, Low, and Informational.

Multiple Select: What types of alerts can Microsoft Sentinel generate?

• a) Security alerts
• b) Compliance alerts
• c) Threat intelligence alerts
• d) System health alerts

Answer: a) Security alerts, c) Threat intelligence alerts, and d) System health alerts.

Explanation: Microsoft Sentinel can generate security alerts, threat intelligence alerts, and system health alerts.

True or False: Microsoft Sentinel allows you to customize alert severity levels to suit your organization’s needs.

• True
• False

Answer: False.

Explanation: Although Microsoft Sentinel provides different severity levels, these levels cannot be customized. They are predefined as High, Medium, Low, and Informational.

Multiple Choice: What is the first step in creating an alert rule in Microsoft Sentinel?

• a) Set the severity level
• b) Define the alert rule name
• c) Choose the log source
• d) Write a KQL query

Answer: b) Define the alert rule name

Explanation: The first step in creating an alert rule in Microsoft Sentinel is defining the alert rule name.

True or False: Alert rules in Microsoft Sentinel have a schedule that defines how often the rule’s logic is applied to events.

• True
• False

Answer: True.

Explanation: In Microsoft Sentinel, each alert rule has an associated schedule that dictates how frequently the rule’s logic is applied to events.

Interview Questions

What is Microsoft Sentinel?

Microsoft Sentinel is a scalable, cloud-native, security information event management (SIEM) and security orchestration automated response (SOAR) solution.

What function do alert rules serve in Microsoft Sentinel?

Alert rules in Microsoft Sentinel serve the purpose of setting the conditions for when an alert should be created from data. These rules analyze the data and generate alerts about any potential threats when certain conditions are met.

How do you create a new alert rule in Microsoft Sentinel?

In Microsoft Sentinel, you can create a new alert rule through ‘Analytics’ in the navigation pane. You then select ‘+Create’ and follow the onscreen prompts to define your rule conditions and action groups.

Can you make use of Microsoft Sentinel’s Built-in templates to create alert rules?

Yes, Microsoft Sentinel comes with a variety of built-in templates that can be used to create and customize alert rules.

How can you customize an alert rule in Microsoft Sentinel?

You can customize an alert rule in Microsoft Sentinel by defining the rule logic either using Kusto Query Language (KQL) or choosing a built-in template. You can also customize the severity level, tactics, and status of the rule, as well as adding entities mapping.

What are the key components of an alert rule in Microsoft Sentinel?

The key components of an alert rule in Microsoft Sentinel include the rule name, description, severity, tactics, status, rule logic (event-based or KQL), alert details, entity mappings, and automated responses.

Can you change an existing alert rule?

Yes, you can change an existing alert rule in the settings page of that particular rule at any time. Changes can be as simple as enabling/disabling the rule to as complex as editing the rule logic.

What is the role of the Kusto Query Language (KQL) in creating an alert rule?

The Kusto Query Language (KQL) is used to precisely define the logic for the alert rule. Users create a query using KQL, and if incoming data matches this query, then an alert is generated.

Can alert rules in Microsoft Sentinel be scheduled?

Yes, alert rules in Microsoft Sentinel can be scheduled to run at specific intervals, allowing for automated and continuous monitoring of your environment.

How are the incidents generated in relation to alert rules?

Incidents in Microsoft Sentinel are generated when an alert rule condition is met. The alert is then attached to a new incident or, based on the grouping settings, to an existing incident.

What is a Scheduled Rule?

A Scheduled Rule in Microsoft Sentinel is a type of Analytics rule that analyzes the data at a regular interval, based on a user-defined schedule. The rule engine uses a user-defined query written in KQL to find matches in the log data.

What is the ‘Suppression’ feature in alert rules?

Suppression feature in alert rules allows you to stop or pause further alert generation for a specific time, reducing the chance of alert fatigue.

Can you clone alert rules in Microsoft Sentinel?

Yes, alert rules in Microsoft Sentinel can be cloned. This feature allows you to quickly create multiple rules that are similar with slight variations.

What role does automation play in relation to alert rules in Microsoft Sentinel?

Automation in relation to alert rules allows for automated response to incidents that these rules generate, helping delegate repetitive tasks to machines and freeing up security analysts to address more complex issues.

Is it possible to test alert rules in Microsoft Sentinel?

Yes, it is possible. When you create or modify an alert rule, you can test it using the ‘Test rule’ functionality. This helps you evaluate the effectiveness of the rule before it’s put into production.