Use Office 365 Audit Log to Report the Deletion of Teams
Idly playing with PowerShell on a dull Friday afternoon in winter, I decided to respond to a question in the Office 365 Facebook group about how to be notified when someone deletes a team. Presumably the requirement exists to allow tenant administrators to leap into action to chastise people who delete teams without asking, or something like that.
My initial response was that this is the same problem as you have when someone deletes an Office 365 Group (each team is a group) and directed the questioner to this 2018 Petri article, which describes how to check groups in a soft-deleted state waiting for their 30-day retention period to expire. During this time, you can rescue a soft-deleted group and return it to full working order.
Office 365 Activity Alerts
The Office 365 Security and Compliance Center includes the ability to create activity alerts (in the Alerts section). These alerts fire when an Office 365 audit record is captured for specific events, like team deletions (Figure 1). When an alert happens, email notifications go to the people specified in the alert to tell them that something’s happened. It all sounds good.
Figure 1: An Office 365 Activity Alert for Team Deletions
The Problems with Activity Alerts
When you access activity alerts in the Security and Compliance Center, you’ll see a banner saying that Microsoft has a better solution (activity policies). Activity alerts have some problems. First, they can fire some time after an event occurs. It all depends when the audit log ingests events from the workload responsible for the monitored activity. Usually the delay is between 15-30 minutes for most Office 365 workloads, but it can be longer. Second, whatever process is responsible for sending the email notifications seems to be asleep for most of the day as the arrival time of the notifications is very unpredictable. You might even say unreliable.
It’s easy to create your own version of activity alerts
based on the same data as used by Office 365. First, we look in the Office 365
audit log for team deletion events. Then we distribute the information via
email or Teams.
Script to Report Team Deletions
The PowerShell script below searches for team deletion events from the last seven days and stores the information in a list object.
<pre class="lang:ps">CLS; Write-Host "Searching Office 365 Audit Records to find Team deletions"
$StartDate = (Get-Date).AddDays(-7); $EndDate = (Get-Date)
$Records = (Search-UnifiedAuditLog -Operations TeamDeleted -StartDate $StartDate -EndDate $EndDate -ResultSize 1000)
If ($Records.Count -eq 0) {
Write-Host "No audit records for Team deletions found." }
Else {
Write-Host "Processing" $Records.Count "team deletion audit records..."
$Report = [System.Collections.Generic.List[Object]]::new() # Create output file
# Scan each audit record to extract information
ForEach ($Rec in $Records) {
$AuditData = ConvertFrom-Json $Rec.Auditdata
$ReportLine = [PSCustomObject] @{
TimeStamp = Get-Date($AuditData.CreationTime) -format g
User = $AuditData.UserId
Action = $AuditData.Operation
Team = $AuditData.TeamName }
$Report.Add($ReportLine) }
}
Cls
Write-Host "All done - Team deletion records for the last 90 days"
$Report | Format-Table TimeStamp, Action, Team, User -AutoSize</pre>
Notifying Administrators About Team Deletions
After we know what teams were deleted in the last week, we
can use the information stored in the $Report variable to create
notifications for administrators that are posted via email or Teams.
Creating and sending email notifications in PowerShell is straightforward (an example is explained here). Remember that the account used to send the message must be enabled for SMTP authentication as otherwise the Send-Message cmdlet will fail.
Posting to a Teams channel can be done using the incoming webhook connector as described in this article. In some respects, it seems appropriate that notifications about deleted teams should be posted to Teams, but I will let you make your own mind up.
The Office 365 Audit log is stuffed full of interesting information to explain how and when things happen inside a tenant. The Office 365 for IT Pros eBook contains many examples of using the audit log to good effect. Subscribe to receive monthly updates full of Office 365 goodness.
Hi Tony, would be interested to know whether a auto-expiration of a Team (using Group Expiration Policies) also triggers the same alert? Or does it not count as user activity
It would be a different audit event because the removal is of the Office 365 Group, not a team, and is performed by a background process. You’d check for Delete Group operations performed by a process with a name like ServicePrincipal_1342cefb-7a89-4ee2-af90-c8443053e1e8
How to best alert about channel deletions? We just lost a couple of channels because someone deleted them by accident and people didn’t realize until after the 21 days grace period. I couldn’t find any trigger for that in the alert policy, but the events can be found under Audit.
{"id":null,"mode":"button","open_style":"in_modal","currency_code":"EUR","currency_symbol":"\u20ac","currency_type":"decimal","blank_flag_url":"https:\/\/office365itpros.com\/wp-content\/plugins\/tip-jar-wp\/\/assets\/images\/flags\/blank.gif","flag_sprite_url":"https:\/\/office365itpros.com\/wp-content\/plugins\/tip-jar-wp\/\/assets\/images\/flags\/flags.png","default_amount":100,"top_media_type":"featured_image","featured_image_url":"https:\/\/office365itpros.com\/wp-content\/uploads\/2022\/11\/cover-141x200.jpg","featured_embed":"","header_media":null,"file_download_attachment_data":null,"recurring_options_enabled":true,"recurring_options":{"never":{"selected":true,"after_output":"One time only"},"weekly":{"selected":false,"after_output":"Every week"},"monthly":{"selected":false,"after_output":"Every month"},"yearly":{"selected":false,"after_output":"Every year"}},"strings":{"current_user_email":"","current_user_name":"","link_text":"Virtual Tip Jar","complete_payment_button_error_text":"Check info and try again","payment_verb":"Pay","payment_request_label":"Office 365 for IT Pros","form_has_an_error":"Please check and fix the errors above","general_server_error":"Something isn't working right at the moment. Please try again.","form_title":"Office 365 for IT Pros","form_subtitle":null,"currency_search_text":"Country or Currency here","other_payment_option":"Other payment option","manage_payments_button_text":"Manage your payments","thank_you_message":"Thank you for supporting the work of Office 365 for IT Pros!","payment_confirmation_title":"Office 365 for IT Pros","receipt_title":"Your Receipt","print_receipt":"Print Receipt","email_receipt":"Email Receipt","email_receipt_sending":"Sending receipt...","email_receipt_success":"Email receipt successfully sent","email_receipt_failed":"Email receipt failed to send. Please try again.","receipt_payee":"Paid to","receipt_statement_descriptor":"This will show up on your statement as","receipt_date":"Date","receipt_transaction_id":"Transaction ID","receipt_transaction_amount":"Amount","refund_payer":"Refund from","login":"Log in to manage your payments","manage_payments":"Manage Payments","transactions_title":"Your Transactions","transaction_title":"Transaction Receipt","transaction_period":"Plan Period","arrangements_title":"Your Plans","arrangement_title":"Manage Plan","arrangement_details":"Plan Details","arrangement_id_title":"Plan ID","arrangement_payment_method_title":"Payment Method","arrangement_amount_title":"Plan Amount","arrangement_renewal_title":"Next renewal date","arrangement_action_cancel":"Cancel Plan","arrangement_action_cant_cancel":"Cancelling is currently not available.","arrangement_action_cancel_double":"Are you sure you'd like to cancel?","arrangement_cancelling":"Cancelling Plan...","arrangement_cancelled":"Plan Cancelled","arrangement_failed_to_cancel":"Failed to cancel plan","back_to_plans":"\u2190 Back to Plans","update_payment_method_verb":"Update","sca_auth_description":"Your have a pending renewal payment which requires authorization.","sca_auth_verb":"Authorize renewal payment","sca_authing_verb":"Authorizing payment","sca_authed_verb":"Payment successfully authorized!","sca_auth_failed":"Unable to authorize! Please try again.","login_button_text":"Log in","login_form_has_an_error":"Please check and fix the errors above","uppercase_search":"Search","lowercase_search":"search","uppercase_page":"Page","lowercase_page":"page","uppercase_items":"Items","lowercase_items":"items","uppercase_per":"Per","lowercase_per":"per","uppercase_of":"Of","lowercase_of":"of","back":"Back to plans","zip_code_placeholder":"Zip\/Postal Code","download_file_button_text":"Download File","input_field_instructions":{"tip_amount":{"placeholder_text":"How much would you like to tip?","initial":{"instruction_type":"normal","instruction_message":"How much would you like to tip? Choose any currency."},"empty":{"instruction_type":"error","instruction_message":"How much would you like to tip? Choose any currency."},"invalid_curency":{"instruction_type":"error","instruction_message":"Please choose a valid currency."}},"recurring":{"placeholder_text":"Recurring","initial":{"instruction_type":"normal","instruction_message":"How often would you like to give this?"},"success":{"instruction_type":"success","instruction_message":"How often would you like to give this?"},"empty":{"instruction_type":"error","instruction_message":"How often would you like to give this?"}},"name":{"placeholder_text":"Name on Credit Card","initial":{"instruction_type":"normal","instruction_message":"Enter the name on your card."},"success":{"instruction_type":"success","instruction_message":"Enter the name on your card."},"empty":{"instruction_type":"error","instruction_message":"Please enter the name on your card."}},"privacy_policy":{"terms_title":"Terms and conditions","terms_body":null,"terms_show_text":"View Terms","terms_hide_text":"Hide Terms","initial":{"instruction_type":"normal","instruction_message":"I agree to the terms."},"unchecked":{"instruction_type":"error","instruction_message":"Please agree to the terms."},"checked":{"instruction_type":"success","instruction_message":"I agree to the terms."}},"email":{"placeholder_text":"Your email address","initial":{"instruction_type":"normal","instruction_message":"Enter your email address"},"success":{"instruction_type":"success","instruction_message":"Enter your email address"},"blank":{"instruction_type":"error","instruction_message":"Enter your email address"},"not_an_email_address":{"instruction_type":"error","instruction_message":"Make sure you have entered a valid email address"}},"note_with_tip":{"placeholder_text":"Your note here...","initial":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"empty":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"not_empty_initial":{"instruction_type":"normal","instruction_message":"Attach a note to your tip (optional)"},"saving":{"instruction_type":"normal","instruction_message":"Saving note..."},"success":{"instruction_type":"success","instruction_message":"Note successfully saved!"},"error":{"instruction_type":"error","instruction_message":"Unable to save note note at this time. Please try again."}},"email_for_login_code":{"placeholder_text":"Your email address","initial":{"instruction_type":"normal","instruction_message":"Enter your email to log in."},"success":{"instruction_type":"success","instruction_message":"Enter your email to log in."},"blank":{"instruction_type":"error","instruction_message":"Enter your email to log in."},"empty":{"instruction_type":"error","instruction_message":"Enter your email to log in."}},"login_code":{"initial":{"instruction_type":"normal","instruction_message":"Check your email and enter the login code."},"success":{"instruction_type":"success","instruction_message":"Check your email and enter the login code."},"blank":{"instruction_type":"error","instruction_message":"Check your email and enter the login code."},"empty":{"instruction_type":"error","instruction_message":"Check your email and enter the login code."}},"stripe_all_in_one":{"initial":{"instruction_type":"normal","instruction_message":"Enter your credit card details here."},"empty":{"instruction_type":"error","instruction_message":"Enter your credit card details here."},"success":{"instruction_type":"normal","instruction_message":"Enter your credit card details here."},"invalid_number":{"instruction_type":"error","instruction_message":"The card number is not a valid credit card number."},"invalid_expiry_month":{"instruction_type":"error","instruction_message":"The card's expiration month is invalid."},"invalid_expiry_year":{"instruction_type":"error","instruction_message":"The card's expiration year is invalid."},"invalid_cvc":{"instruction_type":"error","instruction_message":"The card's security code is invalid."},"incorrect_number":{"instruction_type":"error","instruction_message":"The card number is incorrect."},"incomplete_number":{"instruction_type":"error","instruction_message":"The card number is incomplete."},"incomplete_cvc":{"instruction_type":"error","instruction_message":"The card's security code is incomplete."},"incomplete_expiry":{"instruction_type":"error","instruction_message":"The card's expiration date is incomplete."},"incomplete_zip":{"instruction_type":"error","instruction_message":"The card's zip code is incomplete."},"expired_card":{"instruction_type":"error","instruction_message":"The card has expired."},"incorrect_cvc":{"instruction_type":"error","instruction_message":"The card's security code is incorrect."},"incorrect_zip":{"instruction_type":"error","instruction_message":"The card's zip code failed validation."},"invalid_expiry_year_past":{"instruction_type":"error","instruction_message":"The card's expiration year is in the past"},"card_declined":{"instruction_type":"error","instruction_message":"The card was declined."},"missing":{"instruction_type":"error","instruction_message":"There is no card on a customer that is being charged."},"processing_error":{"instruction_type":"error","instruction_message":"An error occurred while processing the card."},"invalid_request_error":{"instruction_type":"error","instruction_message":"Unable to process this payment, please try again or use alternative method."},"invalid_sofort_country":{"instruction_type":"error","instruction_message":"The billing country is not accepted by SOFORT. Please try another country."}}}},"fetched_oembed_html":false}
Hi Tony,
Interesting to know if a Team auto-expiry would also count as a Team Deletion activity and trigger an alert?
See https://office365itpros.com/2020/01/30/reporting-office-365-group-deletions/
Hi Tony, would be interested to know whether a auto-expiration of a Team (using Group Expiration Policies) also triggers the same alert? Or does it not count as user activity
It would be a different audit event because the removal is of the Office 365 Group, not a team, and is performed by a background process. You’d check for Delete Group operations performed by a process with a name like ServicePrincipal_1342cefb-7a89-4ee2-af90-c8443053e1e8
How to best alert about channel deletions? We just lost a couple of channels because someone deleted them by accident and people didn’t realize until after the 21 days grace period. I couldn’t find any trigger for that in the alert policy, but the events can be found under Audit.