Collect Microsoft Defender for Endpoint logs

Supported in:

Google secops SIEM

This document explains how to ingest Microsoft Defender for Endpoint (Advanced Threat Protection) logs to Google Security Operations using Google Cloud Storage V2.

Microsoft Defender for Endpoint is an enterprise endpoint security platform that provides preventative protection, post-breach detection, automated investigation, and response capabilities. It generates alerts, incidents, device inventory, and advanced hunting telemetry data that can be streamed via the Microsoft Security API to external storage for analysis in Google SecOps.

Before you begin

Make sure you have the following prerequisites:

• A Google SecOps instance
• A GCP project with Cloud Storage API enabled
• Permissions to create and manage GCS buckets
• Permissions to manage IAM policies on GCS buckets
• Permissions to create Cloud Run services, Pub/Sub topics, and Cloud Scheduler jobs
• A Microsoft 365 E5 or Microsoft Defender for Endpoint P2 license
• Global Administrator or Security Administrator role in Microsoft Entra ID (Azure AD)
• An application registered in Microsoft Entra ID with the required API permissions

Create Google Cloud Storage bucket

1. Go to the Google Cloud Console.
2. Select your project or create a new one.
3. In the navigation menu, go to Cloud Storage > Buckets.
4. Click Create bucket.

5. Provide the following configuration details:

   Setting	Value
   Name your bucket	Enter a globally unique name (for example, defender-atp-logs)
   Location type	Choose based on your needs (Region, Dual-region, Multi-region)
   Location	Select the location closest to your Google SecOps instance
   Storage class	Standard (recommended for frequently accessed logs)
   Access control	Uniform (recommended)
   Protection tools	Optional: Enable object versioning or retention policy

6. Click Create.

Register an application in Microsoft Entra ID

1. Sign in to the Microsoft Entra admin center.
2. Go to Identity > Applications > App registrations.
3. Click New registration.
4. Provide the following configuration details:
   • Name: Enter a descriptive name (for example, SecOps-Defender-ATP-Integration)
   • Supported account types: Select Accounts in this organizational directory only
   • Redirect URI: Leave blank
5. Click Register.
6. On the application overview page, copy and save the following values:
   • Application (client) ID
   • Directory (tenant) ID

Create a client secret

1. In the application page, go to Certificates & secrets.
2. Click New client secret.
3. Provide the following configuration details:
   • Description: Enter SecOps Integration Secret
   • Expires: Select an expiration period (for example, 24 months)
4. Click Add.

5. Copy and save the Value of the client secret immediately.

   Note: The client secret value is only displayed once. If you navigate away without copying it, you must create a new secret.

Grant API permissions

1. In the application page, go to API permissions.
2. Click Add a permission.
3. Select APIs my organization uses.
4. Search for and select WindowsDefenderATP.
5. Select Application permissions.
6. Select the following permissions:
   • Alert.Read.All - Read all alerts
   • Machine.Read.All - Read all machine information
   • SecurityRecommendation.Read.All - Read security recommendations
   • Vulnerability.Read.All - Read vulnerability information
   • AdvancedQuery.Read.All - Run advanced queries
7. Click Add permissions.
8. Click Grant admin consent for (your organization).
9. Confirm by clicking Yes.

Verify permissions

1. In the API permissions page, verify that all permissions show Granted for (your organization) in the Status column.
2. If any permissions show Not granted, click Grant admin consent again.

Test API access

• Test your credentials before proceeding with the integration:

  TENANT_ID="<your-tenant-id>"
  CLIENT_ID="<your-client-id>"
  CLIENT_SECRET="<your-client-secret>"
  
  # Get OAuth token
  TOKEN=$(curl -s -X POST "https://login.microsoftonline.com/${TENANT_ID}/oauth2/v2.0/token" \
      -H "Content-Type: application/x-www-form-urlencoded" \
      -d "client_id=${CLIENT_ID}&scope=https://api.securitycenter.microsoft.com/.default&client_secret=${CLIENT_SECRET}&grant_type=client_credentials" | python3 -c "import sys,json;print(json.load(sys.stdin)['access_token'])")
  
  # Test API access
  curl -s -H "Authorization: Bearer ${TOKEN}" "https://api.securitycenter.microsoft.com/api/alerts?\$top=1" | python3 -m json.tool
  

Create service account for Cloud Run function

The Cloud Run function needs a service account with permissions to write to GCS bucket and be invoked by Pub/Sub.

Create service account

1. In the GCP Console, go to IAM & Admin > Service Accounts.
2. Click Create Service Account.
3. Provide the following configuration details:
   • Service account name: Enter defender-atp-collector-sa
   • Service account description: Enter Service account for Cloud Run function to collect Microsoft Defender for Endpoint logs
4. Click Create and Continue.
5. In the Grant this service account access to project section, add the following roles:
   1. Click Select a role.
   2. Search for and select Storage Object Admin.
   3. Click + Add another role.
   4. Search for and select Cloud Run Invoker.
   5. Click + Add another role.
   6. Search for and select Cloud Functions Invoker.
6. Click Continue.
7. Click Done.

These roles are required for:

• Storage Object Admin: Write logs to GCS bucket and manage state files
• Cloud Run Invoker: Allow Pub/Sub to invoke the function
• Cloud Functions Invoker: Allow function invocation

Grant IAM permissions on GCS bucket

Grant the service account write permissions on the GCS bucket:

1. Go to Cloud Storage > Buckets.
2. Click on your bucket name (for example, defender-atp-logs).
3. Go to the Permissions tab.
4. Click Grant access.
5. Provide the following configuration details:
   • Add principals: Enter the service account email (for example, defender-atp-collector-sa@PROJECT_ID.iam.gserviceaccount.com)
   • Assign roles: Select Storage Object Admin
6. Click Save.

Create Pub/Sub topic

Create a Pub/Sub topic that Cloud Scheduler will publish to and the Cloud Run function will subscribe to.

1. In the GCP Console, go to Pub/Sub > Topics.
2. Click Create topic.
3. Provide the following configuration details:
   • Topic ID: Enter defender-atp-trigger
   • Leave other settings as default
4. Click Create.

Create Cloud Run function to collect logs

The Cloud Run function will be triggered by Pub/Sub messages from Cloud Scheduler to fetch logs from Microsoft Defender for Endpoint API and write them to GCS.

1. In the GCP Console, go to Cloud Run.
2. Click Create service.
3. Select Function (use an inline editor to create a function).

4. In the Configure section, provide the following configuration details:

   Setting	Value
   Service name	defender-atp-collector
   Region	Select region matching your GCS bucket (for example, us-central1)
   Runtime	Select Python 3.12 or later

5. In the Trigger (optional) section:

   1. Click + Add trigger.
   2. Select Cloud Pub/Sub.
   3. In Select a Cloud Pub/Sub topic, choose defender-atp-trigger.
   4. Click Save.

6. In the Authentication section:

   1. Select Require authentication.
   2. Check Identity and Access Management (IAM).
   Note: Pub/Sub will automatically handle authentication when invoking the function.

7. Scroll down and expand Containers, Networking, Security.

8. Go to the Security tab:

   • Service account: Select defender-atp-collector-sa

9. Go to the Containers tab:

   1. Click Variables & Secrets.
   2. Click + Add variable for each environment variable:

   Variable Name	Example Value	Description
   GCS_BUCKET	defender-atp-logs	GCS bucket name
   GCS_PREFIX	defender-atp	Prefix for log files
   STATE_KEY	defender-atp/state.json	State file path
   TENANT_ID	your-tenant-id	Microsoft Entra ID tenant ID
   CLIENT_ID	your-client-id	Application (client) ID
   CLIENT_SECRET	your-client-secret	Client secret value
   MAX_RECORDS	10000	Max records per run
   PAGE_SIZE	1000	Records per API page
   LOOKBACK_HOURS	24	Initial lookback period

10. In the Variables & Secrets section, scroll down to Requests:

    • Request timeout: Enter 600 seconds (10 minutes)

11. Go to the Settings tab:

    • In the Resources section:
      • Memory: Select 512 MiB or higher
      • CPU: Select 1

12. In the Revision scaling section:

    • Minimum number of instances: Enter 0
    • Maximum number of instances: Enter 100

13. Click Create.

14. Wait for the service to be created (1-2 minutes).

15. After the service is created, the inline code editor will open automatically.

Add function code

1. Enter main in the Entry point field.

2. In the inline code editor, create two files:

   • First file main.py:

     import functions_framework
     from google.cloud import storage
     import json
     import os
     import urllib3
     from datetime import datetime, timezone, timedelta
     import time
     
     # Initialize HTTP client with timeouts
     http = urllib3.PoolManager(
       timeout=urllib3.Timeout(connect=5.0, read=30.0),
       retries=False,
     )
     
     # Initialize Storage client
     storage_client = storage.Client()
     
     # Environment variables
     GCS_BUCKET = os.environ.get('GCS_BUCKET')
     GCS_PREFIX = os.environ.get('GCS_PREFIX', 'defender-atp')
     STATE_KEY = os.environ.get('STATE_KEY', 'defender-atp/state.json')
     TENANT_ID = os.environ.get('TENANT_ID')
     CLIENT_ID = os.environ.get('CLIENT_ID')
     CLIENT_SECRET = os.environ.get('CLIENT_SECRET')
     MAX_RECORDS = int(os.environ.get('MAX_RECORDS', '10000'))
     PAGE_SIZE = int(os.environ.get('PAGE_SIZE', '1000'))
     LOOKBACK_HOURS = int(os.environ.get('LOOKBACK_HOURS', '24'))
     
     def get_access_token(tenant_id, client_id, client_secret):
       """Get OAuth 2.0 access token from Microsoft Entra ID."""
       token_url = f"https://login.microsoftonline.com/{tenant_id}/oauth2/v2.0/token"
       body = (
         f"client_id={client_id}"
         f"&scope=https%3A%2F%2Fapi.securitycenter.microsoft.com%2F.default"
         f"&client_secret={client_secret}"
         f"&grant_type=client_credentials"
       )
       headers = {'Content-Type': 'application/x-www-form-urlencoded'}
       response = http.request('POST', token_url, body=body.encode('utf-8'), headers=headers)
       if response.status != 200:
         raise Exception(f"Token request failed: {response.status} - {response.data.decode('utf-8')}")
       token_data = json.loads(response.data.decode('utf-8'))
       return token_data['access_token']
     
     def parse_datetime(value):
       """Parse ISO datetime string to datetime object."""
       if value.endswith("Z"):
         value = value[:-1] + "+00:00"
       return datetime.fromisoformat(value)
     
     @functions_framework.cloud_event
     def main(cloud_event):
       """Cloud Run function triggered by Pub/Sub to fetch Defender for Endpoint logs."""
       if not all([GCS_BUCKET, TENANT_ID, CLIENT_ID, CLIENT_SECRET]):
         print('Error: Missing required environment variables')
         return
     
       try:
         bucket = storage_client.bucket(GCS_BUCKET)
         state = load_state(bucket, STATE_KEY)
     
         now = datetime.now(timezone.utc)
         last_time = None
     
         if isinstance(state, dict) and state.get("last_event_time"):
           try:
             last_time = parse_datetime(state["last_event_time"])
             last_time = last_time - timedelta(minutes=2)
           except Exception as e:
             print(f"Warning: Could not parse last_event_time: {e}")
     
         if last_time is None:
           last_time = now - timedelta(hours=LOOKBACK_HOURS)
     
         print(f"Fetching alerts from {last_time.isoformat()} to {now.isoformat()}")
     
         token = get_access_token(TENANT_ID, CLIENT_ID, CLIENT_SECRET)
     
         records, newest_event_time = fetch_alerts(
           token=token,
           start_time=last_time,
           end_time=now,
           page_size=PAGE_SIZE,
           max_records=MAX_RECORDS,
         )
     
         if not records:
           print("No new alert records found.")
           save_state(bucket, STATE_KEY, now.isoformat())
           return
     
         timestamp = now.strftime('%Y%m%d_%H%M%S')
         object_key = f"{GCS_PREFIX}/logs_{timestamp}.ndjson"
         blob = bucket.blob(object_key)
     
         ndjson = '\n'.join([json.dumps(record, ensure_ascii=False) for record in records]) + '\n'
         blob.upload_from_string(ndjson, content_type='application/x-ndjson')
     
         print(f"Wrote {len(records)} records to gs://{GCS_BUCKET}/{object_key}")
     
         if newest_event_time:
           save_state(bucket, STATE_KEY, newest_event_time)
         else:
           save_state(bucket, STATE_KEY, now.isoformat())
     
         print(f"Successfully processed {len(records)} records")
     
       except Exception as e:
         print(f'Error processing logs: {str(e)}')
         raise
     
     def load_state(bucket, key):
       """Load state from GCS."""
       try:
         blob = bucket.blob(key)
         if blob.exists():
           state_data = blob.download_as_text()
           return json.loads(state_data)
       except Exception as e:
         print(f"Warning: Could not load state: {e}")
       return {}
     
     def save_state(bucket, key, last_event_time_iso):
       """Save the last event timestamp to GCS state file."""
       try:
         state = {'last_event_time': last_event_time_iso}
         blob = bucket.blob(key)
         blob.upload_from_string(
           json.dumps(state, indent=2),
           content_type='application/json'
         )
         print(f"Saved state: last_event_time={last_event_time_iso}")
       except Exception as e:
         print(f"Warning: Could not save state: {e}")
     
     def fetch_alerts(token, start_time, end_time, page_size, max_records):
       """Fetch alerts from Microsoft Defender for Endpoint API with pagination."""
       base_url = "https://api.securitycenter.microsoft.com/api/alerts"
       headers = {
         'Authorization': f'Bearer {token}',
         'Accept': 'application/json',
         'Content-Type': 'application/json',
       }
     
       start_iso = start_time.strftime('%Y-%m-%dT%H:%M:%SZ')
       end_iso = end_time.strftime('%Y-%m-%dT%H:%M:%SZ')
     
       filter_query = f"alertCreationTime ge {start_iso} and alertCreationTime le {end_iso}"
       url = f"{base_url}?$filter={filter_query}&$top={page_size}&$orderby=alertCreationTime asc"
     
       records = []
       newest_time = None
       page_num = 0
       backoff = 1.0
     
       while url:
         page_num += 1
     
         if len(records) >= max_records:
           print(f"Reached max_records limit ({max_records})")
           break
     
         try:
           response = http.request('GET', url, headers=headers)
     
           if response.status == 429:
             retry_after = int(response.headers.get('Retry-After', str(int(backoff))))
             print(f"Rate limited (429). Retrying after {retry_after}s...")
             time.sleep(retry_after)
             backoff = min(backoff * 2, 30.0)
             continue
     
           backoff = 1.0
     
           if response.status != 200:
             print(f"HTTP Error: {response.status}")
             response_text = response.data.decode('utf-8')
             print(f"Response body: {response_text}")
             return [], None
     
           data = json.loads(response.data.decode('utf-8'))
           page_results = data.get('value', [])
     
           if not page_results:
             print(f"No more results (empty page)")
             break
     
           print(f"Page {page_num}: Retrieved {len(page_results)} alerts")
           records.extend(page_results)
     
           for alert in page_results:
             try:
               event_time = alert.get('alertCreationTime')
               if event_time:
                 if newest_time is None or parse_datetime(event_time) > parse_datetime(newest_time):
                   newest_time = event_time
             except Exception as e:
               print(f"Warning: Could not parse event time: {e}")
     
           url = data.get('@odata.nextLink')
     
         except Exception as e:
           print(f"Error fetching alerts: {e}")
           return [], None
     
       print(f"Retrieved {len(records)} total records from {page_num} pages")
       return records, newest_time
     

   • Second file requirements.txt:

     functions-framework==3.*
     google-cloud-storage==2.*
     urllib3>=2.0.0
     

3. Click Deploy to save and deploy the function.

4. Wait for deployment to complete (2-3 minutes).

   Note: The Pub/Sub trigger configuration automatically creates the necessary subscriptions and permissions.

Create Cloud Scheduler job

Cloud Scheduler will publish messages to the Pub/Sub topic at regular intervals, triggering the Cloud Run function.

1. In the GCP Console, go to Cloud Scheduler.
2. Click Create Job.

3. Provide the following configuration details:

   Setting	Value
   Name	defender-atp-collector-hourly
   Region	Select same region as Cloud Run function
   Frequency	0 * * * * (every hour, on the hour)
   Timezone	Select timezone (UTC recommended)
   Target type	Pub/Sub
   Topic	Select defender-atp-trigger
   Message body	{} (empty JSON object)

4. Click Create.

Schedule frequency options

Choose frequency based on log volume and latency requirements:

Frequency	Cron Expression	Use Case
Every 5 minutes	*/5 * * * *	High-volume, low-latency
Every 15 minutes	*/15 * * * *	Medium volume
Every hour	0 * * * *	Standard (recommended)
Every 6 hours	0 */6 * * *	Low volume, batch processing

Test the integration

1. In the Cloud Scheduler console, find your job.
2. Click Force run to trigger the job manually.
3. Wait a few seconds.
4. Go to Cloud Run > Services.
5. Click on defender-atp-collector.
6. Click the Logs tab.

7. Verify the function executed successfully. Look for:

   Fetching alerts from YYYY-MM-DDTHH:MM:SS+00:00 to YYYY-MM-DDTHH:MM:SS+00:00
   Page 1: Retrieved X alerts
   Wrote X records to gs://defender-atp-logs/defender-atp/logs_YYYYMMDD_HHMMSS.ndjson
   Successfully processed X records
   

8. Go to Cloud Storage > Buckets.

9. Click on your bucket name (for example, defender-atp-logs).

10. Navigate to the defender-atp/ folder.

11. Verify that a new .ndjson file was created with the current timestamp.

If you see errors in the logs:

• HTTP 401: Check API credentials (TENANT_ID, CLIENT_ID, CLIENT_SECRET) in environment variables
• HTTP 403: Verify the application has the required API permissions and admin consent is granted
• HTTP 429: Rate limiting - function will automatically retry with backoff
• Missing environment variables: Check all required variables are set

Retrieve the Google SecOps service account

Google SecOps uses a unique service account to read data from your GCS bucket. You must grant this service account access to your bucket.

Get the service account email

1. Go to SIEM Settings > Feeds.
2. Click Add New Feed.
3. Click Configure a single feed.
4. In the Feed name field, enter a name for the feed (for example, Defender ATP Logs).
5. Select Google Cloud Storage V2 as the Source type.
6. Select Microsoft Defender for Endpoint as the Log type.
7. Click Get Service Account.

8. A unique service account email will be displayed, for example:

   [e-mail]
   

9. Copy this email address for use in the next step.

   Note: Each Google SecOps instance has a unique service account. Don't use service accounts from other documentation or examples.

10. Click Next.

11. Specify values for the following input parameters:

    • Storage bucket URL: Enter the GCS bucket URI with the prefix path:

      gs://defender-atp-logs/defender-atp/
      

    Note: Always include the trailing slash (/) at the end of the URI.

    • Source deletion option: Select the deletion option according to your preference:

      • Never: Never deletes any files after transfers (recommended for testing).
      • Delete transferred files: Deletes files after successful transfer.
      • Delete transferred files and empty directories: Deletes files and empty directories after successful transfer.
      Note: If you select a deletion option, the service account must have Storage Object Admin role instead of Storage Object Viewer. Update IAM permissions accordingly.

    • Maximum File Age: Include files modified in the last number of days (default is 180 days)

    • Asset namespace: The asset namespace

    • Ingestion labels: The label to be applied to the events from this feed

12. Click Next.

13. Review your new feed configuration in the Finalize screen, and then click Submit.

Grant IAM permissions to the Google SecOps service account

The Google SecOps service account needs Storage Object Viewer role on your GCS bucket.

1. Go to Cloud Storage > Buckets.
2. Click on your bucket name (for example, defender-atp-logs).
3. Go to the Permissions tab.
4. Click Grant access.
5. Provide the following configuration details:
   • Add principals: Paste the Google SecOps service account email
   • Assign roles: Select Storage Object Viewer

6. Click Save.

   Note: If you plan to use the deletion option "Delete transferred files" or "Delete transferred files and empty directories," grant Storage Object Admin role instead of Storage Object Viewer.

UDM mapping table

Log field	UDM mapping	Logic
	metadata.vendor_name	The metadata.vendor_name UDM field is set to Microsoft.
	metadata.product_name	The metadata.product_name UDM field is set to Microsoft Defender for Endpoint.
id	metadata.product_log_id	id log field is mapped to the metadata.product_log_id UDM field.
alertCreationTime	metadata.event_timestamp	alertCreationTime log field is mapped to the metadata.event_timestamp UDM field.
title	security_result.summary	title log field is mapped to the security_result.summary UDM field.
description	security_result.description	description log field is mapped to the security_result.description UDM field.
category	security_result.category_details	category log field is mapped to the security_result.category_details UDM field.
severity	security_result.severity	severity log field is mapped to the security_result.severity UDM field.
status	security_result.detection_fields[status]	status log field is mapped to the security_result.detection_fields UDM field.
classification	security_result.detection_fields[classification]	classification log field is mapped to the security_result.detection_fields UDM field.
determination	security_result.detection_fields[determination]	determination log field is mapped to the security_result.detection_fields UDM field.
investigationState	security_result.detection_fields[investigationState]	investigationState log field is mapped to the security_result.detection_fields UDM field.
computerDnsName	principal.hostname	computerDnsName log field is mapped to the principal.hostname UDM field.
machineId	principal.asset.asset_id	machineId log field is mapped to the principal.asset.asset_id UDM field.
relatedUser.userName	principal.user.userid	relatedUser.userName log field is mapped to the principal.user.userid UDM field.
relatedUser.domainName	principal.administrative_domain	relatedUser.domainName log field is mapped to the principal.administrative_domain UDM field.
threatName	security_result.threat_name	threatName log field is mapped to the security_result.threat_name UDM field.
threatFamilyName	security_result.threat_name	threatFamilyName log field is mapped to the security_result.threat_name UDM field.
detectionSource	security_result.detection_fields[detectionSource]	detectionSource log field is mapped to the security_result.detection_fields UDM field.
evidence	security_result.detection_fields[evidence]	evidence log field is mapped to the security_result.detection_fields UDM field.

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