Use Microsoft Defender for Endpoint APIs

This page describes how to create an application to get programmatic access to Defender for Endpoint on behalf of a user.

If you need programmatic access Microsoft Defender for Endpoint without a user, refer to Access Microsoft Defender for Endpoint with application context.

If you are not sure which access you need, read the Introduction page.

Microsoft Defender for Endpoint exposes much of its data and actions through a set of programmatic APIs. Those APIs will enable you to automate work flows and innovate based on Microsoft Defender for Endpoint capabilities. The API access requires OAuth2.0 authentication. For more information, see OAuth 2.0 Authorization Code Flow.

In general, you’ll need to take the following steps to use the APIs:

• Create an AAD application
• Get an access token using this application
• Use the token to access Defender for Endpoint API

This page explains how to create an AAD application, get an access token to Microsoft Defender for Endpoint and validate the token.

Create an app

1. Log on to Azure with a user account that has the Global Administrator role.
2. Navigate to Azure Active Directory > App registrations > New registration.

   

3. When the wp-signup.php an application page appears, enter your application’s registration information:
   • Name – Enter a meaningful application name that will be displayed to users of the app.
   • Supported account types – Select which accounts you would like your application to support.

     TABLE 1

     Supported account types	Description
     Accounts in this organizational directory only	Select this option if you’re building a line-of-business (LOB) application. This option is not available if you’re not wp-signup.phping the application in a directory.This option maps to Azure AD only single-tenant. This is the default option unless you’re wp-signup.phping the app outside of a directory. In cases where the app is wp-signup.phped outside of a directory, the default is Azure AD multi-tenant and personal Microsoft accounts.
     Accounts in any organizational directory	Select this option if you would like to target all business and educational customers.This option maps to an Azure AD only multi-tenant. If you wp-signup.phped the app as Azure AD only single-tenant, you can update it to be Azure AD multi-tenant and back to single-tenant through the Authentication blade.
     Accounts in any organizational directory and personal Microsoft accounts	Select this option to target the widest set of customers.This option maps to Azure AD multi-tenant and personal Microsoft accounts. If you wp-signup.phped the app as Azure AD multi-tenant and personal Microsoft accounts, you cannot change this in the UI. Instead, you must use the application manifest editor to change the supported account types.

   • Redirect URI (optional) – Select the type of app you’re building, Web or Public client (mobile & desktop), and then enter the redirect URI (or reply URL) for your application.
     • For web applications, provide the base URL of your app. For example, http://localhost:31544 might be the URL for a web app running on your local machine. Users would use this URL to sign in to a web client application.
     • For public client applications, provide the URI used by Azure AD to return token responses. Enter a value specific to your application, such as myapp://auth.

     To see specific examples for web applications or native applications, check out our quickstarts.

     When finished, select wp-signup.php.

4. Allow your Application to access Microsoft Defender for Endpoint and assign it ‘Read alerts’ permission:
   • On your application page, select API Permissions > Add permission > APIs my organization uses > type WindowsDefenderATP and select on WindowsDefenderATP.

      Note

     WindowsDefenderATP does not appear in the original list. Start writing its name in the text box to see it appear.

     

   • Choose Delegated permissions > Alert.Read > select Add permissions.

     

    Important

   Select the relevant permissions. Read alerts is only an example.

   For example:

   • To run advanced queries, select Run advanced queries permission.
   • To isolate a device, select Isolate machine permission.
   • To determine which permission you need, view the Permissions section in the API you are interested to call.
   • Select Grant consent.

      Note

     Every time you add permission you must select on Grant consent for the new permission to take effect.

     

5. Write down your application ID and your tenant ID.

   On your application page, go to Overview and copy the following information:

   

Get an access token

For more information on AAD tokens, see Azure AD tutorial.

Using C#

• Copy/Paste the below class in your application.
• Use AcquireUserTokenAsync method with your application ID, tenant ID, user name, and password to acquire a token.
  C#Copy

  namespace WindowsDefenderATP
  {
      using System.Net.Http;
      using System.Text;
      using System.Threading.Tasks;
      using Newtonsoft.Json.Linq;
  
      public static class WindowsDefenderATPUtils
      {
          private const string Authority = "https://login.microsoftonline.com";
  
          private const string WdatpResourceId = "https://api.securitycenter.microsoft.com";
  
          public static async Task<string> AcquireUserTokenAsync(string username, string password, string appId, string tenantId)
          {
              using (var httpClient = new HttpClient())
              {
                  var urlEncodedBody = $"resource={WdatpResourceId}&client_id={appId}&grant_type=password&username={username}&password={password}";
  
                  var stringContent = new StringContent(urlEncodedBody, Encoding.UTF8, "application/x-www-form-urlencoded");
  
                  using (var response = await httpClient.PostAsync($"{Authority}/{tenantId}/oauth2/token", stringContent).ConfigureAwait(false))
                  {
                      response.EnsureSuccessStatusCode();
  
                      var json = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
  
                      var jObject = JObject.Parse(json);
  
                      return jObject["access_token"].Value<string>();
                  }
              }
          }
      }
  }
  

Validate the token

Verify to make sure you got a correct token:

• Copy/paste into JWT the token you got in the previous step in order to decode it.
• Validate you get a ‘scp’ claim with the desired app permissions.
• In the screenshot below you can see a decoded token acquired from the app in the tutorial:

  

Use the token to access Microsoft Defender for Endpoint API

• Choose the API you want to use – Supported Microsoft Defender for Endpoint APIs.
• Set the Authorization header in the HTTP request you send to “Bearer {token}” (Bearer is the Authorization scheme).
• The Expiration time of the token is 1 hour (you can send more than one request with the same token).
• Example of sending a request to get a list of alerts using C#:
  C#Copy

  var httpClient = new HttpClient();
  
  var request = new HttpRequestMessage(HttpMethod.Get, "https://api.securitycenter.microsoft.com/api/alerts");
  
  request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
  
  var response = httpClient.SendAsync(request).GetAwaiter().GetResult();
  
  // Do something useful with the response
  

Source : Official Microsoft Brand
Editor by : BEST Antivirus KBS Team