Microsoft Defender: Alert Suppression to Whitelist

Overview

If you are experiencing many false or benign positives by trusted infrastructure, you can suppress alerts and create suppression rules by various attributes.

The following instructions can be found on Microsoft’s site:

Suppress an alert and create a new suppression rule

Create custom rules to control when alerts are suppressed or resolved. You can control the context for when an alert is suppressed by specifying the alert title, Indicator of compromise, and the conditions. After specifying the context, you can configure the action and scope on the alert.

1. Select the alert you'd like to suppress. This brings up the Alert management pane.

2. Select Create a suppression rule.

   You can create a suppression condition using these attributes. An AND operator is applied between each condition, so suppression occurs only if all conditions are met.

   • File SHA1

   • File name - wildcard supported

   • Folder path - wildcard supported

   • IP address

   • URL - wildcard supported

   • Command line - wildcard supported

3. Select the Triggering IOC.

4. Specify the action and scope of the alert.

   You can automatically resolve an alert or hide it from the portal. Alerts that are automatically resolved will appear in the resolved section of the alerts queue, alert page, and device timeline and appear resolved across Defender for Endpoint APIs.

   Alerts marked as hidden will be suppressed from the entire system, both on the device's associated alerts and from the dashboard, and will not be streamed across Defender for Endpoint APIs.

5. Enter a rule name and a comment.

6. Click Save.

View the list of suppression rules.

1. In the navigation pane, select Settings > Alert suppression.

2. The list of suppression rules shows all the rules that users in your organization have created.

For more information on managing suppression rules, see

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