Extract Username From Log Text using Powershell - powershell

Question

I'm trying to extract all usernames that has failed login atempts from Event Viewer log and then list only the usernames. However the data for each entry is text so I have a hard time extracting only the names (Intruder123 in this case). It would be a couple of hundred account names stored in an array.
$String = Get-WinEvent #{LogName='Security';ProviderName='Microsoft-Windows-Security-Auditing';ID=4625 } -ComputerName SECRETSERVER |
Select-Object -ExpandProperty Message
$string -match "Account Name: (?<content>.*)"
$matches['content']
The data looks like this (multiple times):
Account For Which Logon Failed:
Security ID: S-1-0-0
Account Name: Intruder123
Account Domain: SECRET.LOCAL

Answer 1

I think you could collect some more information like the time the failed logon happened and on which computer. For that, create a resulting array of objects.
Also, trying to parse the Message property can be cumbersome and I think it is much better to get the info from the Event as XML:
$filter = #{LogName='Security';ProviderName='Microsoft-Windows-Security-Auditing';ID=4625 }
$result = Get-WinEvent -FilterHashtable $filter -ComputerName SECRETSERVER | ForEach-Object {
# convert the event to XML and grab the Event node
$eventXml = ([xml]$_.ToXml()).Event
$userName = ($eventXml.EventData.Data | Where-Object { $_.Name -eq 'TargetUserName' }).'#text'
$computer = ($eventXml.EventData.Data | Where-Object { $_.Name -eq 'WorkstationName' }).'#text'
# output the properties you need
[PSCustomObject]#{
Time = [DateTime]$eventXml.System.TimeCreated.SystemTime
UserName = $userName
Computer = $computer
}
}
# output on screen
$result
# output to CSV file
$result | Export-Csv -Path 'X:\FailedLogons.csv' -NoTypeInformation