Querying Event Logs
I noticed that there is a huge speed difference between using an XML Query and PowerShell Get-EventLog piped through Where-Object to filter event logs. Thanks to this article, I learned how to use the XML Query via PowerShell, so you get the best of both worlds.
Know your version
Here's different commands that will show you which version PowerShell you're running.
$PSVersionTable.PSVersion
Get-Host
$host
$host.version
General concepts
There are two different cmdlets for accessing Windows Event Logs. Get-WinEvent is a newer version of Get-EventLog.
Get-WinEvent
- You have access to more information
- Because you have more information, it might take more effort to filter the data
Get-EventLog
- One clear advantage: you can use the -After and -Before attributes to easily filter results by date
Filtering results
If you want to know how to filter the results, simply pipe the cmdlet to Get-Member:
Get-EventLog system -newest 1 | Get-MemberThe output of the command clearly shows you the methods and properties returned:
PS C:\> Get-EventLog system -newest 1 | Get-Member
TypeName: System.Diagnostics.EventLogEntry#system/nhi/1074012975
Name MemberType Definition
---- ---------- ----------
Disposed Event System.EventHandler Disposed(System.Object, System.EventArgs)
CreateObjRef Method System.Runtime.Remoting.ObjRef CreateObjRef(type requestedType)
Dispose Method void Dispose(), void IDisposable.Dispose()
Equals Method bool Equals(System.Diagnostics.EventLogEntry otherEntry), bool Equals(System.Object obj)
GetHashCode Method int GetHashCode()
GetLifetimeService Method System.Object GetLifetimeService()
GetObjectData Method void ISerializable.GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
GetType Method type GetType()
InitializeLifetimeService Method System.Object InitializeLifetimeService()
ToString Method string ToString()
Category Property string Category {get;}
CategoryNumber Property int16 CategoryNumber {get;}
Container Property System.ComponentModel.IContainer Container {get;}
Data Property byte[] Data {get;}
EntryType Property System.Diagnostics.EventLogEntryType EntryType {get;}
Index Property int Index {get;}
InstanceId Property long InstanceId {get;}
MachineName Property string MachineName {get;}
Message Property string Message {get;}
ReplacementStrings Property string[] ReplacementStrings {get;}
Site Property System.ComponentModel.ISite Site {get;set;}
Source Property string Source {get;}
TimeGenerated Property datetime TimeGenerated {get;}
TimeWritten Property datetime TimeWritten {get;}
UserName Property string UserName {get;}
EventID ScriptProperty System.Object EventID {get=$this.get_EventID() -band 0xFFFF;}
Get-EventLog Examples
# Show available event logs and stats
Get-EventLog -List# get the most recent 10 system log entries
# just change the LogName from System to Application, Security, etc. to access other logs
Get-EventLog -LogName System -Newest 10# get all system logs from the last 4 hours
Get-EventLog -LogName System -After (Get-Date).AddHours(-4)# get all system logs from the last 24 hours
Get-EventLog -LogName System -After (Get-Date).AddDays(-1)# View specific event using the event Index
Get-EventLog -LogName System -Index [Event_Index_Number] | Format-List# get the most recent 10 entries from a specific source
Get-EventLog -LogName System -Source Kerberos -Newest 10
Get-EventLog -LogName System -Source Microsoft-Windows-WLAN-AutoConfig -Newest 10# Get system logs from the last 24 hours from Source WLAN-AutoConfig
Get-EventLog -LogName system -After (Get-Date).AddDays(-1) -Source Microsoft-Windows-WLAN-AutoConfig# get the most recent 10 Error entries
Get-EventLog -LogName Application -EventType Error -Newest 10
Get-EventLog -LogName Security -EventType Error -Newest 10
Get-EventLog -LogName System -EventType Error -Newest 10# Get list of Event Log Sources from the System log from the last 8 hours sorted by log count
Get-EventLog -LogName System -after (Get-Date).AddHours(-8) | Group-Object -Property Source -NoElement | Select-Object -Property Count, Name | Sort-Object -Descending Count# Find logins in the last 24 hours
Get-EventLog system -after (get-date).AddDays(-1) | where {$_.InstanceId -eq 7001}
# Find last computer start
$today = get-date -Hour 0 -Minute 0;
Get-EventLog system -after $today | sort -Descending | select -First 1# Find logins and logoffs in the last 7 days
$logs = get-eventlog system -source Microsoft-Windows-Winlogon -After (Get-Date).AddDays(-7);
$res = @(); ForEach ($log in $logs) {if($log.instanceid -eq 7001) {$type = "Logon"} Elseif ($log.instanceid -eq 7002){$type="Logoff"} Else {Continue} $res += New-Object PSObject -Property @{Time = $log.TimeWritten; "Event" = $type; User = (New-Object System.Security.Principal.SecurityIdentifier $Log.ReplacementStrings[1]).Translate([System.Security.Principal.NTAccount])}};
$res
Get-WinEvent Examples
# Get user Logon / Logoff events
Get-WinEvent -FilterHashtable @{
LogName='System'
ProviderName='Microsoft-Windows-Winlogon'
ID=7001,7002
}Get-WinEvent -FilterHashtable @{
LogName='Application'
ProviderName='.NET Runtime'
Keywords=36028797018963968
ID=1023
Level=2
}
Formatting output
You can see what formatters are available on any system using the following command
Get-Command -Verb Format -Module Microsoft.PowerShell.UtilityBelow is the output on Windows 11 as of 10/31/2023
PS C:\> Get-Command -Verb Format -Module Microsoft.PowerShell.Utility
CommandType Name Version Source
----------- ---- ------- ------
Function Format-Hex 3.1.0.0 Microsoft.PowerShell.Utility
Cmdlet Format-Custom 3.1.0.0 Microsoft.PowerShell.Utility
Cmdlet Format-List 3.1.0.0 Microsoft.PowerShell.Utility
Cmdlet Format-Table 3.1.0.0 Microsoft.PowerShell.Utility
Cmdlet Format-Wide 3.1.0.0 Microsoft.PowerShell.UtilityYou also have access to the following cmdlets for other output formats
Export-CliXml
# Export-Clixml exports an XML representation of an object or objects and stores it in a file
Get-Acl C:\Windows | Export-CliXml -Path .\c-windows-acl.xml# You can use Import-CliXml to save the stored object or objects back to a variable
$WindowsFolderACL = Import-CliXml -Path .\c-windows-acl.xmlExport-Csv
# Export-Csv - Add an example later
Redirecting data with Out-* cmdlets
Out-Host -Paging
Get-Process | Out-Host -Paging | Format-List
Get-Process | Format-List | Out-Host -Paging
Get-Command | Out-Null
Get-Command Get-Command | Out-Printer -Name 'Microsoft Office Document Image Writer'
Get-Process | Out-File -FilePath C:\temp\processlist.txt
Get-Command | Out-File -FilePath c:\temp\output.txt -Width 2147483647
Grouping output
Remember to use the Get-Member cmdlet to see what properties you can use with Sort-Object and -GroupBy
Get-Service -Name win* | Sort-Object StartType | Format-Table -GroupBy StartType -AutoSizePS C:\> Get-Service -Name win* | Sort-Object StartType | Format-Table -GroupBy StartType -AutoSize
StartType: Automatic
Status Name DisplayName
------ ---- -----------
Running Winmgmt Windows Management Instrumentation
Running WinDefend Microsoft Defender Antivirus Service
StartType: Manual
Status Name DisplayName
------ ---- -----------
Stopped WinRM Windows Remote Management (WS-Management)
Running WinHttpAutoProxySvc WinHTTP Web Proxy Auto-Discovery ServiceQuerying for specific logs
System uptime related logs
For the actual current system uptime via PowerShell, look here.
Use this XML Filter in the Windows Event Viewer to create a custom filtered view of Kernel-General "The operating system started at system time..." events.
<QueryList>
<Query Id="0" Path="System">
<Select Path="System">*[System[(EventID='12')]]</Select>
<Select Path="System">*[System[(EventID='13')]]</Select>
</Query>
</QueryList>Actual log message
Log Name: System
Source: Microsoft-Windows-Kernel-General
Date: 5/30/2023 7:48:33 PM
Event ID: 12
Task Category: (1)
Level: Information
Keywords: (128)
User: SYSTEM
Computer: [REDACTED]
Description:
The operating system started at system time 2023-05-31T02:48:32.500000000Z.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Kernel-General" Guid="{a68ca8b7-004f-d7b6-a698-07e2de0f1f5d}" />
<EventID>12</EventID>
<Version>0</Version>
<Level>4</Level>
<Task>1</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000080</Keywords>
<TimeCreated SystemTime="2023-05-31T02:48:33.1346923Z" />
<EventRecordID>74715</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="8" />
<Channel>System</Channel>
<Computer>[REDACTED]</Computer>
<Security UserID="S-1-5-18" />
</System>
<EventData>
<Data Name="MajorVersion">10</Data>
<Data Name="MinorVersion">0</Data>
<Data Name="BuildVersion">19041</Data>
<Data Name="QfeVersion">2075</Data>
<Data Name="ServiceVersion">0</Data>
<Data Name="BootMode">0</Data>
<Data Name="StartTime">2023-05-31T02:48:32.5000000Z</Data>
</EventData>
</Event>Finding account lockouts.
XML Query
Use this XML Filter in the Windows Event Viewer to create a custom filtered view displaying account lockouts.
<QueryList>
<Query Id="0" Path="Security">
<Select Path="Security">
*[
System[(EventID='4740')]
]
</Select>
</Query>
</QueryList>PowerShell Script - Slow method
Get-EventLog -LogName Security | Where-Object {$_.EventID -eq 4740} |
Select-Object -Property TimeGenerated, Source, EventID, InstanceId, MessagePowerShell Script - Fast method
$query = @"
<QueryList>
<Query Id="0" Path="Security">
<Select Path="Security">
*[
System[(EventID='4740')]
]
</Select>
</Query>
</QueryList>
"@
Get-WinEvent -FilterXml $query | Format-ListFinding account lockouts for a particular user.
XML Query
Use this XML Filter in the Windows Event Viewer to create a custom filtered view displaying account lockouts for the administrator user.
<QueryList>
<Query Id="0" Path="Security">
<Select Path="Security">
*[
EventData[Data[@Name='TargetUserName']='administrator']
and
System[(EventID='4740')]
]
</Select>
</Query>
</QueryList>PowerShell Script - Fast method
$query = @"
<QueryList>
<Query Id="0" Path="Security">
<Select Path="Security">
*[
EventData[Data[@Name='TargetUserName']='administrator']
and
System[(EventID='4740')]
]
</Select>
</Query>
</QueryList>
"@
Get-WinEvent -FilterXml $query | Format-ListNPS + Azure MFA Logs - XML Query
XML Filter for custom filtered view that suppresses accounting event logs.
<QueryXML>
<QueryList>
<Query Id="0" Path="System">
<Select Path="System">*[System[Provider[@Name='NPS']]]</Select>
<Select Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and Task = 12552]]</Select>
<Suppress Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and Task = 12552 and (Data='Network Policy Server discarded the accounting request for a user.')]]</Suppress>
<Select Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing']]] and *[EventData[Data[@Name='LogonProcessName'] and (Data='IAS')]]</Select>
<Select Path="AuthNOptCh">*</Select>
<Select Path="AuthZAdminCh">*</Select>
<Select Path="AuthZOptCh">*</Select>
</Query>
</QueryList>
</QueryXML>NPS Logs - XML Query
XML Filter for custom filtered view that suppresses accounting event logs.
<QueryXML>
<QueryList>
<Query Id="0" Path="System">
<Select Path="System">*[System[Provider[@Name='NPS']]]</Select>
<Select Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and Task = 12552]]</Select>
<Suppress Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing'] and Task = 12552 and (Data='Network Policy Server discarded the accounting request for a user.')]]</Suppress>
<Select Path="Security">*[System[Provider[@Name='Microsoft-Windows-Security-Auditing']]] and *[EventData[Data[@Name='LogonProcessName'] and (Data='IAS')]]</Select>
</Query>
</QueryList>
</QueryXML>Disk logs
XML Query
XML Filter for custom filtered view for disk events.
<QueryList>
<Query Id="0" Path="System">
<Select Path="System">*[System[Provider[@Name='disk']]]</Select>
</Query>
</QueryList>VPN Client Logs
PowerShell Query
$query = @"
<QueryList>
<Query Id="0" Path="Application">
<Select Path="Application">*[System[Provider[@Name='RasAuto' or @Name='RasCfg' or @Name='RasClient' or @Name='Rasman' or @Name='Microsoft-Windows-RasServer' or @Name='Microsoft-Windows-RasSstp' or @Name='Microsoft-Windows-EapMethods-RasChap' or @Name='Microsoft-Windows-NcdAutoSetup' or @Name='Microsoft-Windows-NCSI' or @Name='Microsoft-Windows-NetworkProfile']]]</Select>
<Select Path="System">*[System[Provider[@Name='RasAuto' or @Name='RasCfg' or @Name='RasClient' or @Name='Rasman' or @Name='Microsoft-Windows-RasServer' or @Name='Microsoft-Windows-RasSstp' or @Name='Microsoft-Windows-EapMethods-RasChap' or @Name='Microsoft-Windows-NcdAutoSetup' or @Name='Microsoft-Windows-NCSI' or @Name='Microsoft-Windows-NetworkProfile']]]</Select>
</Query>
</QueryList>
"@
$vpnEvents = Get-WinEvent -FilterXml $query -Oldest
# Displays events from the last 24 hours grouped by ProviderName
# This is the best view for easily browsing
$vpnEvents | ?{$_.TimeCreated -ge (Get-Date).Addhours(-24)}# Displays events from the last 24 hours as a time sorted list
$vpnEvents | ?{$_.TimeCreated -ge (Get-Date).Addhours(-24)} | Format-ListXML Query
<QueryList>
<Query Id="0" Path="Application">
<Select Path="Application">*[System[Provider[@Name='RasAuto' or @Name='RasCfg' or @Name='RasClient' or @Name='Rasman' or @Name='Microsoft-Windows-RasServer' or @Name='Microsoft-Windows-RasSstp' or @Name='Microsoft-Windows-EapMethods-RasChap' or @Name='Microsoft-Windows-NcdAutoSetup' or @Name='Microsoft-Windows-NCSI' or @Name='Microsoft-Windows-NetworkProfile']]]</Select>
<Select Path="System">*[System[Provider[@Name='RasAuto' or @Name='RasCfg' or @Name='RasClient' or @Name='Rasman' or @Name='Microsoft-Windows-RasServer' or @Name='Microsoft-Windows-RasSstp' or @Name='Microsoft-Windows-EapMethods-RasChap' or @Name='Microsoft-Windows-NcdAutoSetup' or @Name='Microsoft-Windows-NCSI' or @Name='Microsoft-Windows-NetworkProfile']]]</Select>
</Query>
</QueryList>Searching for Wired/WLAN-AutoConfig related errors
Wired-AutoConfig
#Powershell
$addhours = 12;
# Setup filter for error only logs
$filter = @{ LogName = "Microsoft-Windows-Wired-AutoConfig/Operational"
StartTime = [DateTime]::Now.AddHours($addhours*-1)
EndTime = [DateTime]::Now
Level = 2
}
Write-Host ([DateTime]::Now.AddHours($addhours*-1))
Write-Host ([DateTime]::Now)
$Events = Get-Winevent -FilterHashtable $filter
# Parse out the event message data
ForEach ($Event in $Events) {
# Convert the event to XML
$eventXML = [xml]$Event.ToXml()
# Iterate through each one of the XML message properties
For ($i=0; $i -lt $eventXML.Event.EventData.Data.Count; $i++) {
# Append these as object properties
Add-Member -InputObject $Event -MemberType NoteProperty -Force -Name $eventXML.Event.EventData.Data[$i].name -Value $eventXML.Event.EventData.Data[$i].'#text'
}
}
# Show results stored in variable
$Events | Format-ListWLAN-AutoConfig
#Powershell
$addhours = 12;
# Setup filter for error only logs
$filter = @{ LogName = "Microsoft-Windows-WLAN-AutoConfig/Operational"
StartTime = [DateTime]::Now.AddHours($addhours*-1)
EndTime = [DateTime]::Now
Level = 2
}
Write-Host ([DateTime]::Now.AddHours($addhours*-1))
Write-Host ([DateTime]::Now)
$Events = Get-Winevent -FilterHashtable $filter
# Parse out the event message data
ForEach ($Event in $Events) {
# Convert the event to XML
$eventXML = [xml]$Event.ToXml()
# Iterate through each one of the XML message properties
For ($i=0; $i -lt $eventXML.Event.EventData.Data.Count; $i++) {
# Append these as object properties
Add-Member -InputObject $Event -MemberType NoteProperty -Force -Name $eventXML.Event.EventData.Data[$i].name -Value $eventXML.Event.EventData.Data[$i].'#text'
}
}
$Events | Select-Object id, MachineName, ProcessId,TimeCreated, Adapter, LocalMac, SSID, Cipher, Auth, PeerMac | Format-List
# Show results stored in variable
$Events | Select-Object id, MachineName, ProcessId,TimeCreated, Adapter, LocalMac, SSID, Cipher, Auth, PeerMac | Format-ListShow available wireless profiles and available wireless networks
# show profiles
netsh wlan show profiles
# show available networks
netsh wlan show networksSources: 1