SharePoint Online: How to View Audit Log Reports in Security & Compliance Center?

How to view SharePoint Online Audit Logs?
SharePoint Audit log features are moved to Office 365 Security & Compliance Center unified logging! We can't trim or restrict audit log events in SharePoint Online anymore! If you go to "Audit Log Settings" in site settings, page you'll get:

So, to view audit logs, you should use Office 365 Security & Compliance Center site!

Enable Audit Settings in Office 365
We must turn ON the audit logs feature in the Compliance center before you access the audit logs.

• Log in to the Microsoft Office 365 admin center: https://admin.microsoft.com
• Click on the "Show All" link and then "Compliance" under admin Centers in the left navigation.
• In the Compliance center, Click on the "Audit" link in the left navigation >>  Click on "Start recording user and admin activity" button and give it a minute to complete. In case, you don't see this link or button, that means auditing is already turned ON.
  

You can also enable Audit Logs for SharePoint Online - Office 365 using PowerShell

#Establish Exchange session 
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ `
    -Credential (Get-Credential) -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking | Out-Null

#Enable Audit Log 
If( (Get-AdminAuditLogConfig).UnifiedAuditLogIngestionEnabled)
{
    Write-host "Auditing is already Enabled!" -f Yellow
}
Else
{
    Set-AdminAuditLogConfig -UnifiedAuditLogIngestionEnabled $True
    Write-host "Enabled the Auditing Successfully!" -f Green
}

#Remove the session
Remove-PSSession $Session

How to View SharePoint Online Audit Logs?
Once auditing is enabled, it takes some time (30 min to 24 hours!) to collect data and prepare reports.

• Login to Security and Compliance Center https://compliance.microsoft.com/auditlogsearch or  https://protection.office.com
• Click on "Search" >> "Audit Log Search" from the left navigation.
• In the search panel, You can apply search criteria such as:
• Activities: There are plenty of activities you can choose from.
• Start date and End date: Specify the time duration of the activity
• Users: Define if you need the report for specific users
• File, Folder or Site: Add all or part of the file name, folder name or URL.
  
• Pick relevant activities and other parameters in the search panel. Once set, click on the "Search" button at the bottom to start searching audit logs from SharePoint Online.
  

From the results panel, you can filter the search results and you can also export the result data in CSV format.

Search and Export Office 365 Audit Log using PowerShell:
With PowerShell, you can query Audit log and produce reports. E.g. You may want to generate a report on schedule basis on a specific event such as "External User Invited", "Deleted Items", etc. Here is an example to search and export a unified audit log.

#Get Credentials to connect
$Credential = Get-Credential

#Establish a Exchange Session
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $Credential -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking

#Set Dates
$StartDate = (Get-Date).AddDays(-7)
$EndDate = (Get-Date)

#Search Unified Log
$AuditLog = Search-UnifiedAuditLog -StartDate $StartDate -EndDate $EndDate -ResultSize 5000
$AuditLogResults = $AuditLog.AuditData | ConvertFrom-Json | select CreationTime, UserID, Operation, ClientIP, ObjectID
$AuditLogResults
$AuditLogResults | Export-csv -Path $CSVPath -NoTypeInformation 

Remove-PSSession $Session

This gets all audit logs from all applications from Office 365. Refer to this documentation for all available parameters: https://docs.microsoft.com/en-us/microsoft-365/compliance/search-the-audit-log-in-security-and-compliance?view=o365-worldwide

Get SharePoint Online Audit Logs using PowerShell:
Let's filter SharePoint Online audit logs on files and generate a report with PowerShell.

#Get Credentials to connect
$Credential = Get-Credential

#Establish a Exchange Session
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $Credential -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking

#Set Date Filters - past 24 hours!
$StartDate = (Get-Date).AddDays(-1)
$EndDate = Get-Date

#Search Unified Log
$SharePointLog = Search-UnifiedAuditLog -StartDate $StartDate -EndDate $EndDate -RecordType SharePointFileOperation
$AuditLogResults = $SharePointLog.AuditData | ConvertFrom-Json | Select CreationTime,UserId,Operation, ObjectID,SiteUrl,SourceFileName,ClientIP

#Export Audit log results to CSV
$AuditLogResults
$AuditLogResults | Export-csv -Path "C:\Temp\AuditLog.csv" -NoTypeInformation
Remove-PSSession $Session

To filter all events of a particular user, use:

$AuditLogs = Search-UnifiedAuditLog -StartDate $StartDate -EndDate $EndDate -UserIds "[email protected]"  
$AuditLogResults = $AuditLogs.AuditData | ConvertFrom-Json | Select CreationTime,UserId,Operation,Workload, ObjectID
$AuditLogResults

Similarly, we can filter specific events as:

s#Filter Audit log to Find specific operations
$SiteURLs = @("https://crescentintranet.sharepoint.com/*")
$CSVFile = "C:\Temp\AuditLog.csv"
$Operations = @('PageViewed', 'PageViewedExtended','FileAccessed', 'FileAccessedExtended','FileDeleted')
$FileAccessLog = Search-UnifiedAuditLog -StartDate $StartDate -EndDate $EndDate -Operations $FileAccessOperations -ResultSize 5000 -ObjectIds $SiteURLs
$FileAccessLog.AuditData | ConvertFrom-Json | Select CreationTime,UserId,Operation, ObjectID,SiteUrl,SourceFileName,ClientIP | Export-csv $CSVFile -NoTypeInformation -Force#Filter Audit log to Find specific operations