Powershell log event windows event log

Журнал событий Windows (Event Log) — это важный инструмент, который позволяет администратору отслеживать ошибки, предупреждения и другие информационные сообщения, которые регистрируются операционной системой, ее компонентами и различными программами. Для просмотра журнала событий Windows можно использовать графическую MMC оснастку Event Viewer (
eventvwr.msc
). В некоторых случаях для поиска информации в журналах событий и их анализа гораздо удобнее использовать PowerShell. В этой статье мы покажем, как получать информацию из журналов событий Windows с помощью командлета Get-WinEvent.

На данный момент в Windows доступны два командлета для доступа к событиям в Event Log: Get-EventLog и Get-WinEvent. В подавляющем большинстве случаев рекомендуем использовать именно Get-WinEvent, т.к. он более производителен, особенно в сценариях обработки большого количества событий с удаленных компьютеров. Командлет Get-EventLog является устаревшим и использовался для получения логов в более ранних версиях Windows. Кроме того, Get-EventLog не поддерживается в современных версиях PowerShell Core 7.x.

Получение логов Windows с помощью Get-WinEvent

Для использования команды Get-WinEvent нужно запустить PowerShell с правами администратора (при запуске Get-WinEvent от имени пользователя вы не сможете получить доступ к некоторым логам, например, к Security).

Для получения списка событий из определенного журнала, нужно указать его имя. В данном примере мы выведем последние 20 событий из журнала System:

Get-WinEvent -LogName Application -MaxEvents 20

Чаще всего вам нужно будет получать информацию из журналов System, Application, Security или Setup. Но вы можете указать и другие журналы. Полный список журналов событий в Windows можно получить с помощью команды:

Get-WinEvent -ListLog *

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Например, чтобы вывести события RDP подключений к компьютеру, нужно указать лог Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational:

Get-WinEvent -LogName Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational

Или получить логи SSH подключений к Windows из журнала OpenSSH/Operational:

Get-WinEvent -LogName OpenSSH/Operational

Можно выбрать события сразу из нескольких журналов. Например, чтобы получить информацию о ошибках и предупреждениях из журналов System и Application за последние 24 часа (сутки), можно использовать такой код:

$StartDate = (Get-Date) - (New-TimeSpan -Day 1)
Get-WinEvent Application,System | Where-Object {($_.LevelDisplayName -eq "Error" -or $_.LevelDisplayName -eq "Warning") -and ($_.TimeCreated -ge $StartDate )}

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Чтобы вывести только определенные поля событий, можно использовать Select-Object или Format-Table:

Get-WinEvent -LogName System | Format-Table Machinename, TimeCreated, Id, UserID

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Можно выполнить дополнительные преобразования с полученными данными. Например, в этом примере мы сразу преобразуем имя пользователя в SID:

Get-WinEvent -filterhash @{Logname = 'system'} |
Select-Object @{Name="Computername";Expression = {$_.machinename}},@{Name="UserName";Expression = {$_.UserId.translate([System.Security.Principal.NTAccount]).value}}, TimeCreated

Get-WinEvent: быстрый поиск в событиях Event Viewer с помощью FilterHashtable

Рассмотренный выше способ выбора определенных событий из журналов Event Viewer с помощью Select-Object прост для понимая, но выполняется крайне медленно. Это особенно заметно при выборке большого количества событий. В большинстве случаев для выборки событий нужно использовать фильтрацию на стороне службы Event Viewer с помощью параметра FilterHashtable.

Попробуем сформировать список ошибок и предупреждений за 30 дней с помощью Where-Object и FilterHashtable. Сравнима скорость выполнения этих двух команд PowerShell с помощью Measure-Command:

$StartDate = (Get-Date).AddDays(-30)

Проверим скорость выполнения команды с Where-Object:

(Measure-Command {Get-WinEvent Application,System | Where-Object {($_.LevelDisplayName -eq "Error" -or $_.LevelDisplayName -eq "Warning") -and ($_.TimeCreated -ge $StartDate )}}).TotalMilliseconds

Аналогичная команда с FilterHashtable:

(Measure-Command {Get-WinEvent -FilterHashtable @{LogName = 'System','Application'; Level =2,3; StartTime=$StartDate }})..TotalMilliseconds

В данном примере видно, что команда выборки событий через FilterHashtable выполняется в 30 раз быстрее, чем если бы обычный Where-Object (
2.5
сек vs
76
секунд).

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Если вам нужно найти события по EventID, используйте следующую команду с FilterHashtable:

Get-WinEvent -FilterHashtable @{logname='System';id=1074}|ft TimeCreated,Id,Message

В параметре FilterHashtable можно использовать фильтры по следующим атрибутам событий:

• LogName
• ProviderName
• Path
• Keywords (для поиска успешных событий нужно использовать значение 9007199254740992 или для неуспешных попыток 4503599627370496)
• ID
• Level (1=FATAL, 2=ERROR, 3=Warning, 4=Information, 5=DEBUG, 6=TRACE, 0=Info)
• StartTime
• EndTime
• UserID (SID пользователя)
• Data

Пример поиска события за определенный промежуток времени:

Get-WinEvent -FilterHashTable @{LogName='System'; StartTime=(get-date).AddDays(-7); EndTime=(get-date).AddHours(-1); ID=1234}

Если нужно найти определенный текст в описании события, можно использовать такую команду:

Get-WinEvent -FilterHashtable @{logname='System'}|Where {$_.Message -like "*USB*"}

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Расширенный фильтры событий Get-WinEvent с помощью FilterXml

Фильтры Get-WinEvent с параметром FilterHashtable являются несколько ограниченными. Если вам нужно использовать для выборки событий сложные запросы с множеством условий, нужно использовать параметр FilterXml, который позволяет сформировать запрос на выбор событий в Event Viewer с помощью XML запроса. Как и FilterHashtable, фильтры FilterXml выполняется на стороне сервера, поэтому результат вы получите довольно быстро.

Например, аналогичный запрос для получения последних ошибок из журнала System за последние 30 дней может выглядеть так:

$xmlQuery = @'
<QueryList>
<Query Id="0" Path="System">
<Select Path="System">*[System[(Level=2 or Level=3) and TimeCreated[timediff(@SystemTime) &lt;= 2592000000]]]</Select>
</Query>
</QueryList>
'@
Get-WinEvent -FilterXML $xmlQuery

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Для построения кода сложных XML запросов можно использовать графическую консоль Event Viewer:

1. Запустите
   eventvwr.msc
   ;
2. Найдите журнал для которого вы хотите создать и выберите Filter Current Log;
3. Выберите необходимые параметры запроса в форме. В этом примере я хочу найти события с определенными EventID за последние 7 дней от определенного пользователя;
4. Чтобы получить код XML запроса для параметра FilterXML, перейдите на вкладку XML и скопируйте полученный код (CTRL+A, CTRL+C);
   

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5. Если нужно, вы можете вручную отредактировать данный запрос.

Для экспорта списка событий в CSV файл нужно использовать командлет Export-CSV:

$Events= Get-WinEvent -FilterXML $xmlQuery
$events| Export-CSV "C:\ps\FilterSYSEvents.csv" -NoTypeInformation -Encoding UTF8

Получить логи Event Viewer с удаленных компьютеров

Для получения события с удаленного компьютер достаточно указать его имя в параметре -ComputerName:

$computer='msk-dc01'
Get-WinEvent -ComputerName $computer -FilterHashtable @{LogName="System"; StartTime=(get-date).AddHours(-24)} |   select Message,Id,TimeCreated

Можно опросить сразу несколько серверов/компьютеров и поискать на них определенные события. Список серверов можно получить из текстового файла:

$servers = Get-Content -Path C:\ps\servers.txt

Или из Active Directory:

$servers = (Get-ADComputer -Filter 'operatingsystem -like "*Windows server*" -and enabled -eq "true"').Name
foreach ($server in $servers) {
Get-WinEvent -ComputerName $server -MaxEvents 5 -FilterHashtable @{
LogName = 'System'; ID= 1234
} | Select-Object -Property ID, MachineName
}

Здесь есть другой пример для поиска событий блокировки учетной записи пользователя на всех контроллерах домена:

$Username = 'a.ivanov'
Get-ADDomainController -fi * | select -exp hostname | % {
$GweParams = @{
‘Computername’ = $_
‘LogName’ = ‘Security’
‘FilterXPath’ = "*[System[EventID=4740] and EventData[Data[@Name='TargetUserName']='$Username']]"
}
$Events = Get-WinEvent @GweParams
$Events | foreach {$_.Computer + " " +$_.Properties[1].value + ' ' + $_.TimeCreated}
}

Being able to track what PowerShell scripts are doing is important, especially in a production environment. Recording activity is key to troubleshooting, auditing, and investigating potential security issues. Using PowerShell and a community module known as PSFramework allows you to take your logging to a whole new level which you’ll learn about in this article!

If you find yourself using the Write-Host cmdlet to display error information or manually registering Windows event sources, this article is for you.

Stay with us if you want a simple, scalable PowerShell logging solution that can write to a text file or integrate into a log management solution.

Creating Better Log Messages

Before deciding on how best to generate logs with PowerShell, you need to first understand how to come up with better log messages, to begin with.

There are many reasons to generate logs. One of the most common is the infamous error message. Error messages can be helpful or harmful depending on how you look at things.

You’ve undoubtedly been victim to some bad error messages in your day. If you’ve ever seen the movie Office Space, PC LOAD LETTER is a prime example.

If your error messages cause someone to think, “WTF does that mean?”, you should consider rewriting your message! Logs should be clear and concise.

Make Events Actionable

A log message indicating a cryptic PC LOAD LETTER error message by itself doesn’t make a lot of sense. No one is going to know what that message means including you a few years from now! You should always generate log messages for error conditions that are actionable.

Using the PC LOAD LETTER message for example, what would you think if it instead said, “PC LOAD LETTER: Check the specs on the rotary girder. If within spec, contact vendor support for further guidance“? You’d probably keep your cool a bit more and actually have a jumpstart on fixing the problem.

Keep Logs Simple and Human-Readable

Log information must be human-readable. Include enough information to make the event actionable and not left to guesswork. You can be precise, but make sure you can have someone else understand, even if on a basic level, what the event means.

Logging is only as complicated as you want to make it. Keeping logs simple makes troubleshooting easier for all involved.

Logging Options in Windows

When you hear the word ‘log’ in IT, what comes to mind? Chances are you immediately begin to think about log files. Although log files are, indeed, an option and one you’ll learn about in this article, they aren’t the only option.

Another alternative is the Windows Event Log. The Windows Event Log and it’s seemingly endless number of log sources is ubiquitous in Windows. The event log allows you to write logs the varying degrees of severity, sources, categories, messages, and more.

The Windows Event Log differs from a log file because it has structure. A log file, on its own, is a simple text file. It’s up to the developer to come up with a schema for the log messages. The Windows Event log already has the schema taken care of.

Throughout this article, we’ll cover using PowerShell to work with the event log. We’ll also cover logging with log files using the PSFramework PowerShell module.

Prerequisites

The remainder of this article is going to be a walkthrough. If you’ll be following along, you’ll need to ensure we’re both on the same page. To work through each topic in this article, you’ll need:

• Windows PowerShell 5.1
• intermediate knowledge of PowerShell
• to understand basic Windows event logging terminology

Writing Events to the Windows Event Log

One way to capture logging information with PowerShell is to use the Windows Event Log. As mentioned earlier, the Windows Event Log already provides a schema to work with. It also includes GUI tools like the Windows Event Viewer and PowerShell cmdlets to create and parse event log messages.

The main PowerShell cmdlet you’ll use to write log events to the Windows Event Log is the Write-EventLog cmdlet. The Write-EventLog cmdlet is how you can generate new log events in existing event logs. If you’re planning on using existing event sources like the Application, Security, System event logs, the Write-EventLog cmdlet is all you need.

The Windows Event Log has a concept known as sources. In a nutshell, a source is simply a way to put event log messages into buckets. Built-in sources are used to separate operating system-specific events from software events, for example.

Using existing sources to write events works just fine if you’d like your log message to show up in a default source. But you can also create your own sources which will help differentiate your custom-generated event log messages from all the others.

Creating an Event Log Source

You can create a custom event log source by using the New-EventLog cmdlet. This cmdlet will modify the registry to make your event log a first-class citizen in Windows.

From an administrative PowerShell console, register a new event log source providing a name and source as shown below.

PS51> New-EventLog -LogName 'Application' -Source 'ATA_Script’'

If you don’t have appropriate permissions or are running the command under a non-elevated PowerShell console session, you will see an error like below.

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Creating Event Log Entries

Once you’ve created a source for your script/application, you can then get down to business and begin generating event log messages using the Write-EventLog cmdlet.

Below you can see an example of writing an event log message to the Application event log using the event source just created (ATA_Script). This message is an Informational event with an ID of 1.

PS51> Write-EventLog -LogName 'Application' -Source 'ATA_Script' -EntryType 'Information' -EventID 1 -Message 'Everything is broken. Everything is cool when you’re part of a team!'

Once the event is created, you can then find this event in the Windows Event Viewer or using PowerShell using the Get-WinEvent or the Get-EventLog cmdlet. The below example is using the Get-EventLog cmdlet to find all Informational events using the event source just created. If more than one event is returned, it returns the newest one.

PS51> Get-EventLog -LogName 'Application' -EntryType 'Information' -Source 'ATA_Script’' -Newest 1

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Event Source Best Practice

Before you leave this section, it’s important you know about a gotcha here. In the above example, PowerShell is using the arbitrary registered source (ATA_Script) created earlier. This source is required to write an entry to the Windows Application log.

Using a custom sources like this works well for simple scenarios like:

• Event logging for a custom Windows service.
• Recording results from a simple PowerShell function.
• Providing a trigger event for another process.

As a best practice, register a new event source for each script you want to generate event log entries as shown in the first step. When you do it this way, it’s easier to keep track of what is generating the event log entries. Imagine you have five scripts, each doing a very specific task. If all of them were using the same event source, how could you determine which script had failure? Registering a new event source helps you organize your logging sources.

Leveraging PowerShell Transcripts

Although the method you’re about to learn works, it’s not the best way. You’ll see why in a bit.

Although the Write-Host cmdlet is useful when you need some visual feedback when a script runs, it’s not great at logging. Why?

• The output is specific to a single PowerShell session. When you close the session, the output is gone.
• The cmdlet doesn’t have much customization beyond foreground and background colors of text.

Below you can see an example of what Write-Host cmdlet looks like in use.

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Although by default, this output is only displayed to the PowerShell console and not recorded anywhere else, it can be using PowerShell transcripts.

Using the Start-Transcript cmdlet, you can create transcripts (text files) that capture all output sent to a PowerShell console. The Start-Transcript cmdlet is a great way to record PowerShell session activity.

While the Start-Transcript cmdlet starts recording console activity to a new transcript, the Stop-Transcript cmdlets stops it. You can see an example below.

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Although using the Write-Host cmdlet and PowerShell transcripts technically works, it’s not the greatest solution. Notice what the transcript contains in the example below. The log is difficult to read and is near impossible to parse!

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Logging with the PSFramework PowerShell Module

As promised, it’s time to get into logging to text files! Although, you could roll your own log file solution using a combination of the Add-Content, Set-Content and other PowerShell cmdlets, there’s no need. You can use a free PowerShell module called PSFramework!

PSFramework is a PowerShell module that allows you to log activity in a variety of different scenarios.

Important PSFramework Concepts

Providers

A key concept of the PSFramework module is providers. Providers are pointers to various destinations you’d like logs to be stored in. A provider could be something like Kiwi Log Server, Elasticsearch, loggly, Graylog or something as basic as a file (usually text).

Although extensible, when you first download the PSFramework module, you immediately get three providers to use:

• Filesystem – This provider writes all message streams you create to the currently-logged-in user’s %APPDATA% folder with automatic seven-day retention and rotation. Filesystem is the default provider.
• Gelf – This provider allows PSFramework to send log message streams to an open source log manager called Graylog. There is a little more setup involved when using this option.
• Logfile – This provider allows you to specify a file to write all messages to. Because a log file could be of various types, the default output is CSV-formatted. This means you can use common log file extensions like .txt, .log, or .csv. The choice is yours.

Message Streams

Message streams contain output from commands. These are used to classify information being recorded in the logs. Common streams are Verbose, Debug, Information, Error and Warning. You can read more about available streams using Help about_psf_message .

Let’s get down to actually use the PSFramework module now and see what it can do!

Install PSFramework

The first task is to download and install this module. To do so, download it from the PowerShell Gallery by running Install-Module -Name PSFramework -Scope CurrentUser. This will place the module in my user profile rather than the system path. If you’d like to make the module available to all users on your system, don’t use the Scope parameter.

Once installed, you will now have access to all the cmdlets that are required for the code examples demonstrated in the rest of this article.

Setting up a Provider

There are three registered and installed providers available to choose from with the default PSFramework configuration – filesystem, logfile, and greylog. If you want to use another provider, you will first register and then install that provider within PSFramework. Before you can start writing to logs, you must enable one of these providers.

The command to enable a provider is Set-PSFLoggingProvider. This cmdlet has two required parameters – Name andEnable. You’ll use each parameter to enable the provider or providers you wish to work with.

If you plan on using your own provider, you will need to run the Register-PSFLoggingProvider and the Install-PSFLoggingProvider cmdlets. These cmdlets and scenario are outside the intended scope of this article. If you wish to explore this option further, consult the built-in help provided with the module. There are some examples that could lead you to expanding on existing capabilities and provide you with a deeper understanding of how logging works.

For this demonstration, you’ll be using the logfile provider. Since this provider is off by default, you must first enable the provider so that message streams can be sent to it. Using the Set-PSFLoggingProvider command, you can do that no sweat:

Set-PSFLoggingProvider -Name 'logfile' -Enable $true

If you want to stick with the filesystem provider, no action would be required on your part as it’s already enabled by default.

To see all of the currently-registered providers, run the Get-PSFLoggingProvider command. This command should return output similar to the screenshot below.

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Now that you’ve enabled a provider, you can begin sending message streams to that provider you wish to use for your logging solution.

Logging with the filesystem Provider

The filesystem provider provides a quick way to start logging without having to configure storage locations for log files. It’s perfect for short-term logging needs, but not one where you need long-term diagnostic logging.

In this demonstration of the filesystem provider, you’re going to learn how to use the Write-PSFMessage cmdlet. Imagine you’ve got an existing PowerShell script that starts a service on a remote host. Sometimes the service doesn’t start for some reason and the errors generated are not being captured. You can see the example below.

Invoke-Command -ComputerName 'Lab01.domain.local' -ScriptBlock { Start-Service -Name 'BITS' }

You’d like to know the Start-Service command is able to successfully start the service and when it fails. To do so, you force Start-Service to return a terminating error and then add try/catch blocks to catch any errors that happen.

try {
    Invoke-Command -ComputerName 'Lab01.domain.local' -ScriptBlock { Start-Service -Name 'BITS' } -ErrorAction Stop
} catch {

}

You now need to log both when Start-Service is successful and when it fails. You know that if Invoke-Command fails, PowerShell will run code inside of the catch block and not any code after Invoke-Command runs.

Contrast that behavior with a success where code after Invoke-Command will run. You decide to run theWrite-PSFMessage command in the appropriate spots.

As you can see below, if the code successfully executes, Write-PSFMessage will record a helpful message with a level of Important and tagged as Success.

try {
    Invoke-Command -ComputerName 'Lab01.domain.local' -ScriptBlock { Start-Service -Name 'BITS' } -ErrorAction Stop

    Write-PSFMessage -Level Important -Message 'Successfully started BITS.' -Tag 'Success'
} catch {
    Write-PSFMessage -Level Warning -Message 'Error starting BITS.' -Tag 'Failure' -ErrorRecord $_
}

Above you saw a use of the Tags feature. Tags are optional, but it does make it easier when needing to sort and search a log. Tags are free text allowing you to define your own. Some common tags are SUCCESS, FAILURE, ERROR and INFO.

Now if the command fails, you will see a warning written to the PowerShell console as shown below.

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Viewing the filesystem Log

Once you’ve written a few message streams with the filesystem provider, you can use the Get-PSFMessage cmdlet to query the log.

If the code in the example above generated log messages at the Warning level, you could read all of those messages by using a value of Warning for the Level parameter. You can see an example of how to do this along with the output type you will receive.

PS51> Get-PSFMessage -Level Warning

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Logging with the logfile Provider

Now that you’ve seen how the filesystem provider works, let’s check out the logfile provider. The logfile providers allows you to write message streams to plain-text files, by default, in a CSV format.

To use the logfile provider, you’ll first have to tell PSFramework to not use the default provider (filesystem) and to set a file to record messages to. To do so, use the Set-PSFLoggingProvider cmdlet. You can see in the below example how to do this.

• name of the provider (logfile) via the Name parameter
• setting the Enabled property to True
• setting the destination file as the value for FilePath

PS51> Set-PSFLoggingProvider -Name logfile -Enabled $true -FilePath 'C:\My_Events.log'

Note: Be sure to set the provider at the beginning of your script!

When a message is received via running the Write-PSFMessage command as before, PSFramework will record the message. The message will include a date format of mm:dd:yyyy, script name (source), message level, a verbose message, tag (optional), and an error record.

Below is an example of what a single log message will look like in Windows notepad in an unstructured format.

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To take advantage of the CSV format, open the log file up in Microsoft Excel and the output will look much better as shown below.

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My choice to use the logfile provider instead of the filesystem provider was due to a need to keep a long running history and import information into Excel. The format of the output makes it a breeze to generate charts and filter data for reporting.

Bonus: Querying Logs by Runspace

An advanced feature of the PSFramework module is working with runspaces. A PowerShell runspace is a commonway you can run processes in parallel by spinning up threads.

Since you may have multiple streams of logging running at once in different runspaces, PSFramework allows you to look at multiple logs in real time. These logs can come from many sources through the use of runspaces. This feature is extremely useful as you can leave a single PowerShell session open while running multiple commands or scripts in the background.

If you know the runspace ID, you can specify it using the Runspace parameter on the Get-PSFMessage command as shown below.

Get-PSFMessage -Runspace a2346978-d324-4886-89b8-bd14769be78f

Runspace can be a complicated topic to grasp. If you would like to learn more, check out this Microsoft DevBlog Series about using runspaces.

I’ve been using the PSFramework module for months now and it has supercharged my maintenance scripts and forced me to write better code.

It’s forced me to write better error handling code and to make a habit of setting the common ErrorAction parameter to True on cmdlets to create terminating errors.

I started seeing the benefits instantly. There’s even been an ongoing problem I was able to finally solve using the log file that was generated.

I was running into an error that only occurred when executing a script using scheduled jobs. The script would run fine when executed manually. The issue turned out to be a credential and timing issue. Since the error record ID was in the log file, error messages were clear and using tags, I was able to narrow it down in no time.

Having tried other methods to generate log files and this module is by far the easiest to use.

The PSFramework is module works great, is reliable, and gives you the most control over verbose messages.

Summary

As you’ve learned throughout this article, logging should be a key component of your automation processes. Establishing clear logging guidelines with informative and actionable logs coupled with understanding logging options will go a long way.

If you haven’t used the PSFramework module and haven’t walked through the demos provided here, please do so. This helpful module allows you to many different options in recording logs which will ultimately help troubleshooting, auditing and security analysis.

Further Reading

• PSFramework Documentation
• Friedrich Weinmann: Logging in a DevOps World
• How to Use PowerShell Transcripts by Adam Bertram

The `Get-WinEvent` cmdlet in PowerShell retrieves events from the Windows Event Log or from event log files, allowing users to filter and analyze system, application, and security events efficiently.

Here’s a code snippet to illustrate its usage:

Get-WinEvent -LogName Application -MaxEvents 10

PowerShell Get-WinEvent is a powerful cmdlet used for managing and gathering information from the Windows Event Logs. Designed as a more modern alternative to the older `Get-EventLog` cmdlet, `Get-WinEvent` allows system administrators and advanced users to access a wider variety of logs, including both the traditional Windows logs and custom logs created by applications.

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Why Use Get-WinEvent?

Utilizing Get-WinEvent provides numerous advantages:

• Performance Enhancements: It is optimized to handle larger amounts of data and process logs more quickly than its predecessors.
• Flexibility: It allows you to filter, sort, and manipulate event data, making it easier to find what you need.
• Rich Data: The cmdlet retrieves extensive details about events, enabling in-depth system analysis.

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Understanding Event Logs in Windows

Types of Windows Event Logs

Windows Event Logs can be broadly categorized as follows:

• Application Logs: Contains entries related to applications and their performance.
• System Logs: Captures system-level events, such as driver or hardware issues.
• Security Logs: Focuses on security-related events, like login attempts and access to files.
• Custom Logs: Allows applications to generate their own logs for specific needs.

Structure of Event Logs

Each event log entry has a consistent structure that generally includes the following:

• Timestamp: The date and time the event occurred.
• Event ID: A unique identifier for the event type.
• Level: Severity of the event, categorized as Warning, Error, or Information.
• Source and Message: Specific information about what triggered the event and a description.

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Getting Started with Get-WinEvent

Basic Syntax of Get-WinEvent

The basic syntax of the `Get-WinEvent` command is as follows:

Get-WinEvent -LogName <LogName>

Running Your First Get-WinEvent Command

To retrieve entries from the Application log, you would execute:

Get-WinEvent -LogName Application

This command will fetch all records in the Application log, allowing you to start exploring what each entry contains.

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Filtering Events with Get-WinEvent

Using Filters for Specific Logs

One of the strengths of Get-WinEvent is the ability to filter logs effectively. For instance, if you want to find only the error events within the System log, you could write:

Get-WinEvent -LogName System | Where-Object { $_.Level -eq 'Error' }

This command retrieves only those events classified as Errors, helping you quickly identify critical issues.

Using Event IDs for Specific Issues

Events can also be filtered by their Event ID. For example, to check for logon events, you might use:

Get-WinEvent -LogName Security -Id 4624

Event ID 4624 indicates a successful logon. Tracking logon events is essential for security audits.

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Customizing Output

Selecting Properties to Display

Sometimes, logs contain a wealth of information. To display only specific properties, you can customize your output like this:

Get-WinEvent -LogName Application | Select-Object TimeCreated, ProviderName, Message

This command will show only the creation time, provider name, and the message associated with each event, making it easier to review.

Exporting Event Logs to CSV

You may need to analyze logs further, and saving them for later use can be beneficial. You can export log entries into a CSV file with:

Get-WinEvent -LogName System | Export-Csv -Path "SystemEvents.csv" -NoTypeInformation

This command creates a CSV file containing all System log entries, facilitating easier manipulation and review in spreadsheet applications.

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Advanced Usage of Get-WinEvent

Combining Get-WinEvent with Other Cmdlets

To enhance data manipulation, `Get-WinEvent` can be combined with other cmdlets like `Sort-Object`. For example, to retrieve Application logs sorted by their timestamp in descending order:

Get-WinEvent -LogName Application | Sort-Object TimeCreated -Descending

This command presents the most recent events first, which is particularly useful in troubleshooting scenarios.

Using Get-WinEvent with Filters and Time Windows

You can further narrow down your searches by specifying a time frame. For example, to find System events from the last week, you would use:

Get-WinEvent -LogName System -StartTime (Get-Date).AddDays(-7) -EndTime (Get-Date)

This command efficiently filters events that occurred in the last seven days, making your log reviews more focused.

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Practical Scenarios for Get-WinEvent

Monitoring System Health

Using `Get-WinEvent` can be invaluable in monitoring system health. By regularly checking logs for specific warnings or errors, you can proactively address potential issues before they escalate into critical failures.

Security Auditing with Event Logs

In the realm of security, `Get-WinEvent` is a critical tool. It allows you to track user activities, such as logins and file access, enabling you to identify unauthorized access attempts or other suspicious behavior.

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Conclusion

To conclude, PowerShell Get-WinEvent is an essential cmdlet for effective event log management on Windows systems. Its flexibility, power, and ease of use make it an invaluable tool for system administrators. By mastering `Get-WinEvent`, you enhance your ability to troubleshoot issues, monitor system health, and perform security audits efficiently.

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FAQs about PowerShell Get-WinEvent

• What types of logs can be retrieved?
  You can retrieve logs from the Application, System, Security, and custom logs created by applications.

• How can Get-WinEvent improve troubleshooting processes?
  By quickly accessing detailed event logs, you can identify issues faster, leading to more effective troubleshooting and resolution.