This article is contributed. See the original author and article here.

 


Overview & Use Case


 


Thanks to @Ofer_Shezaf  and @Yaniv Shasha for the brainstorming, contributing and proof reading! 


 


A multi-national organization having multiple branches with different identities across the globe, each branch have it’s own separate tenant (AAD & O365) logs and the global SOC team are looking for a way on how to ingest these logs coming from all branches to their main parent tenant via Azure Sentinel.


 


While Azure Sentinel can’t natively do that using the out-of-the box data connectors (Office 365 / Azure AD), we cover your back with O365 & AAD Multi-Tenancy custom connector via an Azure Sentinel Playbook (Logic App) that invoke the Office 365 Management API & Graph API to read from multiple tenants and writes to a custom table in Sentinel, same can be done using Azure Function.


 


Implementation


 


With the help of Office 365 Management API & Microsoft Graph API we can invoke specific content types cross-tenants:


 





































APIContent-Type / Activity Log
Office 365 Management APIAudit.AzureActiveDirectory
Office 365 Management APIAudit.Exchange
Office 365 Management APIAudit.SharePoint
Office 365 Management APIAudit.General (includes all other workloads not included in the previous content types)
Office 365 Management APIDLP.All (DLP events only for all workloads)
Graph APIaudit-Logs
Graph APISign-in Logs

 


So, tell us more about the steps?


 


Assuming, we have a parent tenant (Pt) & a child tenant (Ct) and the requirements is to invoke the “Ct” tenant O365 Management API & Graph APIs to pull Office 365 & AAD logs and ingest at “Pt” ones.


 


Step(1): Prep & App Registration



  • Ensure that “Ct” Office 365 Security & Compliance audit logs is enabled 


  • Log in to “Ct” Azure tenant, http://portal.azure.com

  • Search for App Registration > New Registration

  • Type Name, ensure of selecting the right “supported account type”: Accounts in any organizational directory (Any Azure AD directory – Multitenant), then click Register button

  • Follow the below gif / step-by step guide on how to define and configure the API permissions & create the secret:


O365MultiConnector1.gif



  • Click at “API permissions”

    • Add a permission > Office 365 Management API > Application permissions

    • Select and check “ActivityFeed.Read” , “ActivityFeed.ReadDlp” & “ServiceHealth.Read”

    • Add a permission > Microsoft Graph

    • Select and check “Directory.Read.All”, “AuditLog.Read.All”

    • Click at “grant admin consent” link



  • Click at “Certificates & secrets”

    • Under Client secrets > Add client secret



  • Get the following values:

    • Application / Client ID

    • Tenant ID

    • Secret

    • Azure Active Directory Domain



  • Register the API subscription via PowerShell, run the below PowerShell as administrator and connect to the “Ct” tenant directory, ensure of replacing $ClientID, $ClientSecret, $tenantdomain and $TenantGUID with the above copied values:


 


 

Connect-AzAccount # connect via child "Pt" admin account

# Populate with App ID and Secret from your Azure AD app registration 
$ClientID = "<Client_ID>"  
$ClientSecret = "<Secret>"  
$loginURL = "https://login.microsoftonline.com/"  
$tenantdomain = "<tenant-domain>.onmicrosoft.com"  
# Get the tenant GUID from Properties | Directory ID under the Azure Active Directory section 
$TenantGUID = "<tenant_ID>"  
$resource = "https://manage.office.com"  
$body = @{grant_type="client_credentials";resource=$resource;client_id=$ClientID;client_secret=$ClientSecret} 
$oauth = Invoke-RestMethod -Method Post -Uri $loginURL/$tenantdomain/oauth2/token?api-version=1.0 -Body $body  
$headerParams = @{'Authorization'="$($oauth.token_type) $($oauth.access_token)"}   
$publisher = New-Guid
Invoke-WebRequest -Method Post -Headers $headerParams -Uri "https://manage.office.com/api/v1.0/$tenantGuid/activity/feed/subscriptions/start?contentType=Audit.AzureActiveDirectory&PublisherIdentifier=$Publisher" 
Invoke-WebRequest -Method Post -Headers $headerParams -Uri "https://manage.office.com/api/v1.0/$tenantGuid/activity/feed/subscriptions/start?contentType=DLP.ALL&PublisherIdentifier=$Publisher" 
Invoke-WebRequest -Method Post -Headers $headerParams -Uri "https://manage.office.com/api/v1.0/$tenantGuid/activity/feed/subscriptions/start?contentType=Audit.General&PublisherIdentifier=$Publisher" 
Invoke-WebRequest -Method Post -Headers $headerParams -Uri "https://manage.office.com/api/v1.0/$tenantGuid/activity/feed/subscriptions/start?contentType=Audit.Exchange&PublisherIdentifier=$Publisher" 
Invoke-WebRequest -Method Post -Headers $headerParams -Uri "https://manage.office.com/api/v1.0/$tenantGuid/activity/feed/subscriptions/start?contentType=Audit.SharePoint&PublisherIdentifier=$Publisher" 

 


 


 


Step(2): Cross-Tenants Custom Connector



O365MultiConnectorPlaybookPart1.gif


 


O365MultiConnectorPlaybookPart3.gif


 


O365MultiConnectorPlaybookPart4.gif


 


Notes & Consideration


 



  • You can customize the parsers at the connector’s flow with the required and needed attributed / fields based on your schema / payload before the ingestion process, also you can create custom Azure Functions once the data being ingested to Azure Sentinel

  • Azure Function can be used to create custom connector for multi-tenant access, here’s a great example created by Jon Nord invoking Office 365 Management API which you can extend and add Graph API as well.

  • Couple of points to be considered while using Logic Apps:



 


Get started today!


 


We encourage you to try it now!


You can also contribute new connectors, workbooks, analytics and more in Azure Sentinel. Get started now by joining the Azure Sentinel Threat Hunters GitHub community.


 

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.

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