Migrate advanced hunting queries from Microsoft Defender for Endpoint

Článok
04/22/2024

Applies to:

Microsoft Defender XDR

Move your advanced hunting workflows from Microsoft Defender for Endpoint to proactively hunt for threats using a broader set of data. In Microsoft Defender XDR, you get access to data from other Microsoft 365 security solutions, including:

Microsoft Defender for Endpoint
Microsoft Defender for Office 365
Microsoft Defender for Cloud Apps
Microsoft Defender for Identity

Note

Most Microsoft Defender for Endpoint customers can use Microsoft Defender XDR without additional licenses. To start transitioning your advanced hunting workflows from Defender for Endpoint, turn on Microsoft Defender XDR.

You can transition without affecting your existing Defender for Endpoint workflows. Saved queries remain intact, and custom detection rules continue to run and generate alerts. They will, however, be visible in Microsoft Defender XDR.

Schema tables in Microsoft Defender XDR only

The Microsoft Defender XDR advanced hunting schema provides additional tables containing data from various Microsoft 365 security solutions. The following tables are available only in Microsoft Defender XDR:

Table name	Description
AlertEvidence	Files, IP addresses, URLs, users, or devices associated with alerts
AlertInfo	Alerts from Microsoft Defender for Endpoint, Microsoft Defender for Office 365, Microsoft Defender for Cloud Apps, and Microsoft Defender for Identity, including severity information and threat categories
EmailAttachmentInfo	Information about files attached to emails
EmailEvents	Microsoft 365 email events, including email delivery and blocking events
EmailPostDeliveryEvents	Security events that occur post-delivery, after Microsoft 365 has delivered the emails to the recipient mailbox
EmailUrlInfo	Information about URLs on emails
IdentityDirectoryEvents	Events involving an on-premises domain controller running Active Directory (AD). This table covers a range of identity-related events and system events on the domain controller.
IdentityInfo	Account information from various sources, including Microsoft Entra ID
IdentityLogonEvents	Authentication events on Active Directory and Microsoft online services
IdentityQueryEvents	Queries for Active Directory objects, such as users, groups, devices, and domains

Important

Queries and custom detections which use schema tables that are only available in Microsoft Defender XDR can only be viewed in Microsoft Defender XDR.

Map DeviceAlertEvents table

The AlertInfo and AlertEvidence tables replace the DeviceAlertEvents table in the Microsoft Defender for Endpoint schema. In addition to data about device alerts, these two tables include data about alerts for identities, apps, and emails.

Use the following table to check how DeviceAlertEvents columns map to columns in the AlertInfo and AlertEvidence tables.

Tip

In addition to the columns in the following table, the AlertEvidence table includes many other columns that provide a more holistic picture of alerts from various sources. See all AlertEvidence columns

DeviceAlertEvents column	Where to find the same data in Microsoft Defender XDR
`AlertId`	`AlertInfo` and `AlertEvidence` tables
`Timestamp`	`AlertInfo` and `AlertEvidence` tables
`DeviceId`	`AlertEvidence` table
`DeviceName`	`AlertEvidence` table
`Severity`	`AlertInfo` table
`Category`	`AlertInfo` table
`Title`	`AlertInfo` table
`FileName`	`AlertEvidence` table
`SHA1`	`AlertEvidence` table
`RemoteUrl`	`AlertEvidence` table
`RemoteIP`	`AlertEvidence` table
`AttackTechniques`	`AlertInfo` table
`ReportId`	This column is typically used in Microsoft Defender for Endpoint to locate related records in other tables. In Microsoft Defender XDR, you can get related data directly from the `AlertEvidence` table.
`Table`	This column is typically used in Microsoft Defender for Endpoint for additional event information in other tables. In Microsoft Defender XDR, you can get related data directly from the `AlertEvidence` table.

Adjust existing Microsoft Defender for Endpoint queries

Microsoft Defender for Endpoint queries will work as-is unless they reference the DeviceAlertEvents table. To use these queries in Microsoft Defender XDR, apply these changes:

Replace DeviceAlertEvents with AlertInfo.
Join the AlertInfo and the AlertEvidence tables on AlertId to get equivalent data.

Original query

The following query uses DeviceAlertEvents in Microsoft Defender for Endpoint to get the alerts that involve powershell.exe:

DeviceAlertEvents
| where Timestamp > ago(7d)
| where AttackTechniques has "PowerShell (T1086)" and FileName == "powershell.exe"

Modified query

The following query has been adjusted for use in Microsoft Defender XDR. Instead of checking the file name directly from DeviceAlertEvents, it joins AlertEvidence and checks for the file name in that table.

AlertInfo
| where Timestamp > ago(7d)
| where AttackTechniques has "PowerShell (T1086)"
| join AlertEvidence on AlertId
| where FileName == "powershell.exe"

Migrate custom detection rules

When Microsoft Defender for Endpoint rules are edited on Microsoft Defender XDR, they continue to function as before if the resulting query looks at device tables only.

For example, alerts generated by custom detection rules that query only device tables will continue to be delivered to your SIEM and generate email notifications, depending on how you've configured these in Microsoft Defender for Endpoint. Any existing suppression rules in Defender for Endpoint will also continue to apply.

Once you edit a Defender for Endpoint rule so that it queries identity and email tables, which are only available in Microsoft Defender XDR, the rule is automatically moved to Microsoft Defender XDR.

Alerts generated by the migrated rule:

Are no longer visible in the Defender for Endpoint portal (Microsoft Defender Security Center)
Stop being delivered to your SIEM or generate email notifications. To work around this change, configure notifications through Microsoft Defender XDR to get the alerts. You can use the Microsoft Defender XDR API to receive notifications for customer detection alerts or related incidents.
Won't be suppressed by Microsoft Defender for Endpoint suppression rules. To prevent alerts from being generated for certain users, devices, or mailboxes, modify the corresponding queries to exclude those entities explicitly.

If you edit a rule this way, you will be prompted for confirmation before such changes are applied.

New alerts generated by custom detection rules in Microsoft Defender XDR are displayed in an alert page that provides the following information:

Alert title and description
Impacted assets
Actions taken in response to the alert
Query results that triggered the alert
Information on the custom detection rule

Write queries without DeviceAlertEvents

In the Microsoft Defender XDR schema, the AlertInfo and AlertEvidence tables are provided to accommodate the diverse set of information that accompany alerts from various sources.

To get the same alert information that you used to get from the DeviceAlertEvents table in the Microsoft Defender for Endpoint schema, filter the AlertInfo table by ServiceSource and then join each unique ID with the AlertEvidence table, which provides detailed event and entity information.

See the sample query below:

AlertInfo
| where Timestamp > ago(7d)
| where ServiceSource == "Microsoft Defender for Endpoint"
| join AlertEvidence on AlertId

This query yields many more columns than DeviceAlertEvents in the Microsoft Defender for Endpoint schema. To keep results manageable, use project to get only the columns you are interested in. The example below projects columns you might be interested in when the investigation detected PowerShell activity:

AlertInfo
| where Timestamp > ago(7d)
| where ServiceSource == "Microsoft Defender for Endpoint"
    and AttackTechniques has "powershell"
| join AlertEvidence on AlertId
| project Timestamp, Title, AlertId, DeviceName, FileName, ProcessCommandLine

If you'd like to filter for specific entities involved in the alerts, you can do so by specifying the entity type in EntityType and the value you would like to filter for. The following example looks for a specific IP address:

AlertInfo
| where Title == "Insert_your_alert_title"
| join AlertEvidence on AlertId
| where EntityType == "Ip" and RemoteIP == "192.88.99.01"

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