deepblue/windows-itpro-docs
1
0
Fork 0
mirror of https://github.com/MicrosoftDocs/windows-itpro-docs.git synced 2025-05-13 05:47:23 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

Update custom-detection-rules.md

Browse Source 
Editing the file directly to reduce back and forth.
This commit is contained in:
Louie Mayor 2019-10-01 07:49:08 -07:00 committed by GitHub
parent 06a38e3bc5
commit 010644b58b
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
windows/security/threat-protection/microsoft-defender-atp/custom-detection-rules.md
View File

@ -36,13 +36,15 @@ In Microsoft Defender Security Center, go to **Advanced hunting** and select an
> [!NOTE] > [!NOTE]
> To use a query for a custom detection rule, the query must return the `EventTime`, `MachineId`, and `ReportId` columns in the results. Queries that don’t use the `project` operator to customize results usually return these common columns. > To use a query for a custom detection rule, the query must return the `EventTime`, `MachineId`, and `ReportId` columns in the results. Queries that don’t use the `project` operator to customize results usually return these common columns.
> [Example] The sample query below counts the number of unique machines (`MachineId`) with antivirus detections and uses this count to find only the machines with more than five detections. To return the latest `EventTime` and the corresponding `ReportId`, it uses the `summarize` operator with the `arg_max` function.
> MiscEvents
```
MiscEvents
| where EventTime > ago(7d) | where EventTime > ago(7d)
| where ActionType == "AntivirusDetection" | where ActionType == "AntivirusDetection"
| summarize (EventTime, ReportId)=arg_max(EventTime, ReportId), count() by MachineId | summarize (EventTime, ReportId)=arg_max(EventTime, ReportId), count() by MachineId
| where count_ > 5 | where count_ > 5
This will fetch the EventTime and ReportId of the latest event from multiple events returned by the query and adds the count by MachineId. ```
### 2. Create new rule and provide alert details. ### 2. Create new rule and provide alert details.