Interpreting Audit Records for Teams Meeting Recordings (Again)

Change in Audit Records for Teams Meeting Recordings Since 2021

Three years ago, I wrote about how to use audit records to track the creation of Teams meeting recordings. The idea was to find the audit records created when a Teams meeting recording was uploaded to OneDrive for Business or SharePoint Online.

Time marches on and old blogs rot, as do old PowerShell scripts. Three years ago, Microsoft hadn’t completed the transition from Stream classic to Stream on SharePoint. The migration finished recently and Microsoft has moved to standardize how Teams meeting recordings and transcripts are stored in OneDrive for Business. Of course, OneDrive only holds recordings for personal meetings. Recordings for channel meetings, including Meet Now in the channel, end up in the SharePoint Online site belonging to the host team.

Closing a Compliance Gap

While some might think that I spend endless hours examining audit records, this is a fallacy. I check on an as required basis, which means that I didn’t notice that my script wasn’t working quite so well because the format of the audit records changed. One important change is that the user noted in all the audit records is app@sharepoint, the ubiquitous SharePoint utility account. No trace exists in the audit records about the user who recorded the meeting, as had happened before.

From a compliance perspective, this is a big deal. Audit records exist to track the actions taken by individuals and system processes, and in this case, it seems important to know who initiated a recording.

Unfortunately, there’s nothing in the audit record to indicate who initiated the recording of a channel message, so we’re left with the SharePoint app. Recordings for personal meetings used to end up in the OneDrive account of the user who started the recording (the organizer or a presenter). Some time ago, Microsoft changed this to a more logical arrangement where recordings always go into the meeting organizer’s OneDrive account. The URL of a OneDrive account contains the site URL, like:

https://office365itpros-my.sharepoint.com/personal/jane_ryan_office365itpros_com

Figuring Out the OneDrive Site Owner

It’s easy for a human to read the URL and know that the OneDrive account belongs to Jane.Ryan@office365itpros.com. With time, I could parse the URL to extract the email address, but I went for a simpler (faster) approach. I used the Get-SPOSite cmdlet from the SharePoint Online PowerShell module to fetch the set of OneDrive accounts in the tenant and created a hash table from the site URL and site owner. It’s fast to check the hash table with the site URL taken from an audit record to return the user principal name of the site owner:

$User = $OneDriveHashTable[$AuditData.SiteURL]
If ($null -eq $User) {
   $User = "SharePoint app"
}

Changes in Search-UnifiedAuditLog Too!

Another influence on the output was the change made by Microsoft in summer 2023 to how the Search-UnifiedAuditLog cmdlet works. Microsoft have denied to me that they did anything, but the evidence shows that:

• The SessionCommand parameter must now be set to ReturnLargeSet to force the cmdlet to return more than 120 records.
• Many more duplicate records are returned than before. This necessitates sorting by the unique audit event identifier to remove the duplicates.
• Search-UnifiedAuditLog returns unsorted data. If a sorted set is important to you, make sure that you sort the audit records by creation date.

$Records = $Records | Sort-Object Identity -Unique | Sort-Object {$_.CreationDate -as [datetime]} -Descending

Of course, you can try to run high completeness searches with Search-UnifiedAuditLog, but I have not had good luck with this preview feature.

Figure 1 shows the output from the updated script, which is available from GitHub. Normal service is resumed.

A Reminder to Check Audit Log Analysis Scripts

It would be nice if a script lasted a little longer, but the ongoing change within Microsoft 365 means that PowerShell developers need to keep a wary eye on updates that might affect production scripts. In this instance, the confluence of the Stream migration and the change to the Search-UnifiedAuditLog cmdlet made a mess of a perfectly good script. I guess life is like that sometimes. Maybe now is a good time to check your scripts that use the Search-UnifiedAuditLog cmdlet.

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