Analyze audit logs

Audit logs provide valuable insights into the activity and security of your Microsoft 365 Messaging environment. By carefully analyzing these logs, you can gain a better understanding of user behavior, detect potential security threats, and ensure compliance with regulatory requirements. In this article, we will explore how to analyze audit logs related to Microsoft 365 Messaging and discuss some key scenarios where this analysis can be beneficial.

Scenarios for Audit Log Analysis

To get started, it is important to note that audit logs capture the details of user and administrator activities across various Microsoft 365 services, including Exchange Online, SharePoint Online, and Teams. These logs can be accessed and analyzed using the Microsoft 365 Security & Compliance Center or by utilizing the Microsoft Graph API.

Let’s focus on auditing logs specifically related to Microsoft 365 Messaging, which includes Exchange Online and Outlook. Here are some common scenarios where analyzing these logs can prove useful:

1. Detecting unauthorized access attempts: By examining the audit logs, you can identify any suspicious logins or failed login attempts. Look for events related to “UserLoggedIn” or “UserLoginFailed” to track who is accessing your messaging services and whether there are any unauthorized attempts.
2. Monitoring mailbox activities: Audit logs help you keep track of actions performed on mailboxes, such as email deletions, email forwarding, or changes to mailbox permissions. Look for events like “MessageDeleted” or “SendAsPermissionChanges” to keep a close eye on mailbox activities.
3. Identifying email abuse or data leakage: Analyzing audit logs can help you identify any misuse of email services, such as sending an unusually large number of emails within a short period or forwarding sensitive company information to external recipients. Look for events like “MessageSent” or “MessageRead” to flag potential email abuse or data leakage incidents.
4. Tracking mailbox and distribution list creations: Audit logs provide insights into when new mailboxes or distribution lists are created. This can be particularly useful for managing your messaging environment and ensuring that only authorized entities are creating or modifying these objects.
5. Monitoring administrator activities: Audit logs allow you to track activities performed by administrators, such as adding new mailbox permissions or modifying user settings. This helps in identifying any unauthorized administrative actions or potential security concerns.

How to Analyze Audit Logs

To analyze the audit logs effectively, you can leverage the power of the Microsoft 365 Security & Compliance Center. This centralized platform offers various features to simplify the log analysis process. Here are some steps to get you started:

1. Sign in to the Microsoft 365 Security & Compliance Center (https://protection.office.com) using your administrator credentials.
2. Navigate to Search > Audit log search in the left-hand menu.
3. Specify the search criteria based on the scenarios mentioned earlier. For example, select “Exchange” in the Activities dropdown to filter the logs specifically related to Exchange Online.
4. Apply additional filters, such as date range, users, or actions, to narrow down the search results and focus on relevant events.
5. Once you have specified the search criteria, click on Search to retrieve the audit logs matching your query.
6. Analyze the search results to identify patterns, anomalies, or any actions that require attention. You can sort, filter, and export the logs as needed.

While the Microsoft 365 Security & Compliance Center provides a user-friendly interface, you can also utilize the Microsoft Graph API to programmatically access and analyze the audit logs. This allows you to automate log analysis tasks or integrate them into your existing monitoring systems.

Here’s an example of using the Microsoft Graph API to retrieve audit logs related to Microsoft 365 Messaging using PowerShell:

$accessToken = ""
$uri = "https://graph.microsoft.com/v1.0/auditLogs/signIns?$filter=resourceDisplayName eq 'Exchange'"
$headers = @{
"Authorization" = "Bearer $accessToken"
}

$response = Invoke-RestMethod -Uri $uri -Headers $headers -Method GET
Write-Output $response


In this example, the code retrieves sign-in events related to Exchange Online using the Microsoft Graph API. You would need to replace <Your access token> with a valid access token obtained through the Microsoft Identity Platform.

Analyzing audit logs related to Microsoft 365 Messaging is crucial for maintaining a secure and compliant messaging environment. By leveraging the capabilities of the Microsoft 365 Security & Compliance Center or the Microsoft Graph API, you can gain valuable insights into user activities, detect potential security threats, and ensure regulatory compliance. Start using audit log analysis today to enhance the security and efficiency of your messaging infrastructure.