Tag Archive: MDE

New features in Advanced Hunting – Microsoft 365 Defender

During Ignite, Microsoft has announced a new set of features in the Advanced Hunting in Microsoft 365 Defender.

These features will definitely help you in the Threat Hunting process and also reduce the gap between analysts, responders and threat hunters and simplify the life of a threat hunter.

Multi-tab support

When having hunting training classes, I usually recommend to use multiple browser tabs. One for the query development, and one used to go back to previous queries to see how some things were done earlier.

for example, if you are developing a hunting query and need an if statement, external data, regex or other more advanced features it is easier to just open a previous query to see how it was solved last time. At least until you get more fluent in KQL. This is to avoid having to save your new query, go back to the old one, and then back to the new again

With the multi-tab support we can open the query in a new tab

Resource usage

The new Hunting Page will now provide the resource usage for the query both timing and an indicator of the resource usage

This will make it easy to see when query optimization is recommended and needed.
You could for example use equals, has instead of contains, remove columns not used to reduce the dataset etc. Of course, when it’s feasible.

If you would like to learn more about how to optimize queries, please visit:

https://docs.microsoft.com/en-us/microsoft-365/security/defender/advanced-hunting-best-practices?view=o365-worldwide

UX

Schema, Functions, Queries and Detection Rules have been separated into tabs for, according to my opinion, easier access and pivoting which will give a better overview in each tab.

Schema Reference

The schema reference will open as a side pane




When looking at one of the *events tables, the ActionType column is very useful to see which events are being logged.
Earlier, I usually selected distinct ActionType in the query to have a look at the events being logged. Now, it’s possible to use the quick access from the portal to expand all action types for a specific table.

Above image shows the action types for DeviceFileEvents. In the DeviceEvents there are around 180 different action types to query.

For the hunting query development and hunting use-cases, the action types is a great go-to resource.

The columns in the schema reference is clickable and can in a simple way be added to the query

Simple query management

Inspect record

The inspect record pane is an easy way to see the data for one single row. When developing new queries I usually take a subset of data (take/limit 20) to see an overview of the results, and also select an event to see all data instead of side scrolling through all columns when needed.

New features in inspect record is that we can do quick filters which will be added to the query.

In this example we would like to know more about process executions from the C:\AttackTools folder

If we would like other pre-defined FolderPath filters, we can select View more filters for FolderPath
We can continue the query development and as in below example, get the count for each file in the folder specified in the query.

Last but definitely not leastLink the query results to an incident

This is my favorite, this will reduce the gap and simplify the process between threat hunters, responders, and analysts.

By selecting the relevant events in the result, they can be added to an existing incident, or create a new incidents.

This feature will help organizations to define the threat hunting both in a proactive hunting scenario, and in a reactive, post breach scenario when the hunters will assist analysts and responder with a simplified process.

How to link the data to an incident

To be able to link the data you need to have the following columns in the output

  • Timestamp
  • DeviceId/AccountObjectID/AccountSid/RecipientEmailAddress (Depending on query table)
  • ReportId

Develop and run the query

Please note, you cannot have multiple queries in the query window when linking to incident

Choose to create a new incident or link to an existing

Add the necessary details and click next
Select the impacted entities
After finishing the wizard, the data will end up in a new alert in the incident

Last tip

Run a quick check in your environment to see if you have remote internet-based logon attempts on your devices by looking for RemoteIPType == “Public”. There are other where RemoteIPType is useful, like processes communicating with Internet.

Happy Hunting!

Download quarantined files is GA

As announced by Microsoft last week, the Download quarantined files is generally available.

This will simplify for SecOps to download quarantined files for further analysis.

So, why do SecOps want to download files?

One reason could be that they want to do forensic analysis on the file to see if taken response actions was enough or extract indicator which they can hunt for.

The feature is enabled in advanced features and is enabled by default

MDATP Settings – Microsoft 365 security

Cloud protection integration

The file download is dependent on the sample submission settings. Make sure it’s turned on!

Requirements 

The file download is available from multiple pages in defender

It’s also visible on the file page, and the reason why we want to have the option to download in multiple pages is to avoid having to switch view and to be able to take the actions where we are in the portal

Update

The possibility to set password for the file download makes it more safe and also avoid file to be detected during download

Live response API – build your custom playbooks

PUBLIC PREVIEW FEATURE

We have been able to use Live Response for some time now. It’s really great and we can take the response actions we find necessary and download data from the endpoint through the browser session.

Here is a very high level of how the architecture looks for the live response feature

Some things which may be difficult today with the limitations of single session is we can only connect to one machine at the time and automation does not apply for a browser session

If a machine is compromised in any way it’s useful, but if we want to automate the responses or run the same custom playbook for multiple devices we need to use the API

The API can be used both to collect necessary artefacts from devices, and also take remediation actions.

On some events, we’ve presented how to use the Live Response to dump memory and export the dmp files to Azure storage as an example how powerful it is.

Requirements

Requirements and limitations

  1. Rate limitations for this API are 10 calls per minute (additional requests are responded with HTTP 429).
  2. 25 concurrently running sessions (requests exceeding the throttling limit will receive a “429 – Too many requests” response).
  3. If the machine is not available, the session will be queued for up to 3 days.
  4. RunScript command timeouts after 10 minutes.
  5. Live response commands cannot be queued up and can only be executed one at a time.
  6. If the machine that you are trying to run this API call is in an RBAC device group that does not have an automated remediation level assigned to it, you’ll need to at least enable the minimum Remediation Level for a given Device Group.
  7. Multiple live response commands can be run on a single API call. However, when a live response command fails all the subsequent actions will not be executed.

Minimum Requirements

Before you can initiate a session on a device, make sure you fulfill the following requirements:

Set up service principle with API access

Sample code to connect with the service principle

Connecting to M365Defender

Connect to MDE API ( which applies to this case)

Request

Header

NameTypeDescription
AuthorizationStringBearer<token>. Required.
Content-Typestringapplication/json. Required.

Body

ParameterTypeDescription
CommentStringComment to associate with the action.
CommandsArrayCommands to run. Allowed values are PutFile, RunScript, GetFile.

Available commands

Command TypeParametersDescription
PutFileKey: FileNameValue: <file name>Puts a file from the library to the device. Files are saved in a working folder and are deleted when the device restarts by default.
RunScriptKey: ScriptName
Value: <Script from library>Key: Args
Value: <Script arguments>
Runs a script from the library on a device.The Args parameter is passed to your script.Timeouts after 10 minutes.
GetFileKey: Path
Value: <File path>
Collect file from a device. NOTE: Backslashes in path must be escaped.

Sample Live response request body

Use can upload your own scripts to the library and call the scripts in a similar way as when you use interactive Live Response

POST https://api.securitycenter.microsoft.com/api/machines/1e5bc9d7e413ddd7902c2932e418702b84d0cc07/runliveresponse


{
   "Commands":[
      {
         "type":"RunScript",
         "params":[
            {
               "key":"ScriptName",
               "value":"minidump.ps1"
            },
            {
               "key":"Args",
               "value":"OfficeClickToRun"
            }

         ]
      },
      {
         "type":"GetFile",
         "params":[
            {
               "key":"Path",
               "value":"C:\\windows\\TEMP\\OfficeClickToRun.dmp.zip"
            }
         ]
      }
   ],
   "Comment":"Testing Live Response API"
}

For further reading, please visit

https://docs.microsoft.com/en-us/microsoft-365/security/defender-endpoint/run-live-response

Happy Hunting!

Microsoft 365 Defender connector for Azure Sentinel in public preview

365 defender connector

A new connector for Microsoft 365 Defender is in public preview in Azure Sentinel. This connector makes it possible to ingest the hunting data into Sentinel

Currently, the Defender for Endpoint Data is available

To enable

  • Go to you Azure Sentinel Instance and select Connectors
  • Search for Microsoft 365 Defender
365 defender connector
  • Click Open Connector Page
  • Select which Events you want to ingest
threat hunting data
  • Click Apply Changes

Example queries

//Registry events
DeviceRegistryEvents
| where ActionType == "RegistryValueSet"
| where RegistryValueName == "DefaultPassword"
| where RegistryKey has @"SOFTWAREMicrosoftWindows NTCurrentVersionWinlogon"
| project Timestamp, DeviceName, RegistryKey
| top 100 by Timestamp
//Process and Network events
union DeviceProcessEvents, DeviceNetworkEvents
| where Timestamp > ago(7d)
| where FileName in~ ("powershell.exe", "powershell_ise.exe")
| where ProcessCommandLine has_any("WebClient",
"DownloadFile",
"DownloadData",
"DownloadString",
"WebRequest",
"Shellcode",
"http",
"https")
| project Timestamp, DeviceName, InitiatingProcessFileName,
InitiatingProcessCommandLine,
FileName, ProcessCommandLine, RemoteIP, RemoteUrl, RemotePort, RemoteIPType
log view

If we look at the tables we can see the new created tables

table view

More information about the data in these tables is available in this post https://blog.sec-labs.com/2018/06/threat-hunting-with-windows-defender-atp/

For further reading: