Entra / Microsoft 365 · Compliance & audit
Report audit rec failed sign in
Search the unified audit log for failed user login audit records.
Connect & set up
Run these once per session. All scopes are read-only unless the script makes changes.
Connect-ExchangeOnline -SkipLoadingCmdletHelp
Run it
The main script. Copy it, or download the .ps1 and run it from your console.
param([int] $LookbackDays = 90)$Modules = Get-Module | Select-Object -ExpandProperty NameIf ("ExchangeOnlineManagement" -notin $Modules) {Write-Host "Loading Exchange Online Management module"Connect-ExchangeOnline -SkipLoadingCmdletHelp}Write-Host "Searching for failed login audit records..."[array]$Records = Search-UnifiedAuditLog -StartDate (Get-Date).AddDays(-$LookbackDays) -EndDate (Get-Date).AddDays(+1) `-Operations UserLoginFailed -SessionCommand ReturnLargeSet -ResultSize 5000 -FormattedIf ($Records.Count -eq 0) {Write-Host "No audit records found for failed logins."break}# Remove any duplicates and sort by date$Records = $Records | Sort-Object Identity -Unique | Sort-Object { $_.CreationDate -as [datetime]} -DescendingWrite-Host "Processing" $Records.Count "audit records..."$Report = [System.Collections.Generic.List[Object]]::new()ForEach ($Rec in $Records) {$AuditData = ConvertFrom-Json $Rec.Auditdata$ReportLine = [PSCustomObject]@{TimeStamp = $Rec.CreationDateUser = $AuditData.UserIdAction = $AuditData.OperationStatus = $AuditData.ResultStatusIpAddress = $AuditData.ActorIpAddressError = $AuditData.LogonErrorUserAgent = $AuditData.ExtendedProperties.value[0]}$Report.Add($ReportLine)}$Report | Sort-Object User, Timestamp | Select-Object Timestamp, User, IpAddress, UserAgent | Out-GridView
Parameters
ParameterDefaultNotes
-LookbackDays90Number of days back to search the unified audit log.Attribution
Author
Office365itpros