Getting Started with Microsoft Sentinel - Hunt For Threats (Part 1)

 

To read part 2, please click here

Overview

Security analysts and investigators always want to be proactive in threat hunting, but, the loads of data generated from various systems and security appliances making it difficult to covert them into meaningful events. Hence, Microsoft Sentinel comes to the rescue with its powerful hunting search and query tools, that are of great help in hunting threats across an organization's vast data sources. 

Use Built-in Queries

Built-in hunting queries are created by Microsoft security researchers on a continuous basis, simultaneously updating them. These queries can be used before, after, and during a compromise to take the following actions:

• Before incident occurs- Proactive action should be taken by running threat-hunting queries related to the ingested data at least once a week. Its results will offer early insight into the events confirming any compromise, or weak spots in an environment that are vulnerable. 

• During a compromise- A livestream should be used to run a query, so that the results can be seen on real-time basis. It can also be used to actively monitor user events, like, to verify whether a specific compromise is still taking place, to determine the threat actor's next move, and finally confirm that the compromise is over.

• After a compromise- Ensure the improvisation of the security coverage and insight to prevent similar incidents in the future.
• According to the compromise occurred, modify the existing queries or create new ones to help in early detection.
• If there is a hunting query for high value insights into possible attacks, custom detection rules should be created based on that query and surface the insights as alerts to the security incident responders.

Hunting and livestream queries can also be created over the data stored in Azure Data Explorer. 

Use the Hunting Dashboard

The hunting dashboard helps in running all the queries, or selected subset, in a single selection. The following table describes detailed actions available from the hunting dashboard: 

Action	Description
See how queries apply to an environment.	Select the Run all queries button, or choose a subset of queries via the checkboxes to the left of each row and select the Run selected queries button. However, running your queries may take some time or a few minutes according to the number of selected queries, time range, and the amount of queried data.
View the queries that returned results	After running the queries, view the queries that returned results via Results filter- 1.     Sort the queries with the most and least results. 2.     View the queries that are inactive in an environment by choosing N/A in the Results filter. 3.     Hover over the info icon (i) next to N/A to know the required data sources to make the query active.
Identify spikes in your data	This can be done by filtering or sorting data on Results delta or Results delta percentage. It compares the last 24 hours results against ones from the previous 24-48 hours, to highlight any significant difference or relative difference in volume.
View queries mapped to MITRE ATT&CK techniques	Queries mapped to MITRE ATT&CK techniques can be filtered or sort via Technique filter. Open a query and select the technique to see its description.
View queries mapped to the MITRE ATT&CK tactic	The MITRE ATT&CK tactic bar at the top of the table, contains the number of queries mapped to each MITRE ATT&CK tactic. This bar is updated dynamically on the current set of filters applied. It allows to view which tactic shows up when you filter by a given result count, a high result data, N/A results, or any other set of filters.
Save a query to your favorites	Queries saved to favorites automatically runs whenever the Hunting page is accessed. Own hunting query or clone can be created and an existing hunting query template can be customized.
Run queries	On the hunting query details page, select Run Query, to directly run the query. The number of matches will be displayed in the Results column. Review the list of hunting queries and their matches.
Review an underlying query	A quick review of an underlying query can be done in the query details pane. Click on the View query results link or the View Results button to see the results. The query will open in the Logs blade to display the matches for the query.

 

To read part 2, please click here