Table of Contents
Alert suppression in Microsoft Security Operations is a critical feature that helps to reduce noise from recurring or unactionable alerts, thereby enabling security analysts to focus on high-priority events. Suppression rules can be used to tailor the flow of alerts to match an organization’s specific security posture and operational requirements.
Alert suppression rules allow you to define conditions under which certain alerts should be automatically suppressed, meaning they won’t be actively presented to analysts. These rules can be based on various factors, such as the frequency of an alert, its source, or the threat it represents.
To create alert suppression rules in the Microsoft Security Center, follow the steps below:
Suppose you have an alert for multiple failed login attempts on a service account that is known to cause issues with a legacy application. Instead of receiving alerts every time the application behaves as expected (and causes failed login attempts), you set up a suppression rule:
You can manage alert suppression rules through the same Microsoft Security Center interface:
An important aspect of managing rules is to periodically review suppression policies to ensure they are still relevant and not hiding critical alerts.
Rule Name | Criteria | Suppression Logic | Duration |
---|---|---|---|
Legacy App Login Fail | Source IP: 10.1.2.3; Account: svc_legacy_app | Within 10 min of initial alert | Indefinite |
Frequent Scanner Alert | Alert Title: Scanner detection; Source IP: list of scanner IPs | More than 5 alerts in 1 hour | 6 months |
Non-critical Service Fail | Alert Title: Service failure; Severity: Informational | Any | Indefinite |
Weekend Maintenance Jobs | Alert Category: Maintenance; Time: Weekends | Any | 1 year |
In conclusion, alert suppression rules in Microsoft Security Operations provide a robust mechanism for streamlining security alert management. By carefully crafting and maintaining these rules, organizations can greatly improve the efficiency and effectiveness of their security operations teams, ensuring that analysts are focusing their efforts on the most pressing and relevant security incidents.
Answer: A
Explanation: Alert suppression rules can be applied to alerts of any severity level to reduce noise from repetitive or known benign alerts.
Answer: C
Explanation: In Microsoft Sentinel, suppression rules can be created based on specific conditions such as the entities involved (e.g., IP addresses, users).
Answer: B
Explanation: Suppressing all alerts for a specific threat without investigation is not an appropriate use of alert suppression rules, as it may lead to missing genuine security incidents.
Answer: B
Explanation: Alert suppression rules in Microsoft Defender for Endpoint can be edited after creation to adjust their conditions or disable them as needed.
Answer: D
Explanation: Azure Security Center allows you to create suppression rules that can be triggered by specifying conditions, such as the type of alert.
Answer: A
Explanation: Suppression rules in Microsoft Defender for Identity can be time-based, allowing certain alerts to be suppressed during specific time intervals.
Answer: C
Explanation: The primary purpose of implementing alert suppression rules is to manage the volume of alerts effectively by suppressing less critical, repetitive, or false-positive alerts, thereby enabling security analysts to focus on high-fidelity alerts.
Answer: A
Explanation: Alert suppression rules can be applied to alerts triggered by both custom and built-in detection rules to avoid alert fatigue.
Answer: B
Explanation: Regularly reviewing and adjusting suppression rules is considered a best practice to ensure that the rules are still relevant and that critical alerts are not being suppressed inadvertently.
Answer: A
Explanation: Each Microsoft security product (e.g., Microsoft Defender for Endpoint, Microsoft Defender for Identity) has its own mechanism for creating and managing alert suppression rules. They usually need to be set up separately for each product.
Answer: B
Explanation: After creating an alert suppression rule, it is important to validate that it works as intended by checking whether the correct alerts are being suppressed without affecting others.
Answer: D
Explanation: Suppression rules in Microsoft Defender for Office 365 can be used to reduce false positives across all protection areas, including phishing attempts, malware detections, and spam detections.
Alert suppression rules enable you to temporarily suppress alerts from being generated in Azure Security Center.
You might want to create an alert suppression rule when you know that an alert generated in Azure Security Center is a false positive, or when you know that a legitimate activity will generate alerts that you don’t need to see.
You can create a new alert suppression rule in Azure Security Center by navigating to the Security alerts page, selecting an alert that you want to suppress, and then clicking the “Suppress” button.
Yes, you can apply alert suppression rules to multiple alerts at once by selecting the alerts you want to suppress and then clicking the “Suppress” button.
You can view existing alert suppression rules in Azure Security Center by navigating to the Security alerts page, clicking the “Manage alert suppression rules” link, and then selecting the alert suppression rule you want to view.
You can edit an existing alert suppression rule in Azure Security Center by navigating to the Security alerts page, clicking the “Manage alert suppression rules” link, and then selecting the alert suppression rule you want to edit.
Yes, you can set an expiration date for an alert suppression rule to automatically stop suppressing alerts after a certain date.
You can delete an existing alert suppression rule in Azure Security Center by navigating to the Security alerts page, clicking the “Manage alert suppression rules” link, selecting the alert suppression rule you want to delete, and then clicking the “Delete” button.
Yes, you can export alert suppression rules from Azure Security Center as a JSON file.
Yes, you can import alert suppression rules into Azure Security Center by uploading a JSON file containing the suppression rules.
If this material is helpful, please leave a comment and support us to continue.