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Event Viewer

Violet Hansen edited this page Oct 27, 2024 · 10 revisions

Windows Event Viewer

This document is dedicated to offering various ways to use Event logs to achieve different purposes.


How to identify which Windows Firewall rule is responsible for a blocked packet

I've mostly considered this for the Country IP Blocking category, but you can use it for any purpose.

Before doing this, you need to activate one of the system Audits.

I suggest doing it using GUI because it will have a permanent effect:

image


Or you can activate that Audit using this command, but it will only temporarily activate it and it'll be disabled again after you restart Windows.

For Systems With English Locale Only

Auditpol /set /category:"System" /SubCategory:"Filtering Platform Packet Drop" /success:enable /failure:enable

For Systems With Any Locale

Auditpol /set /category:"{69979848-797A-11D9-BED3-505054503030}" /SubCategory:"{0CCE9225-69AE-11D9-BED3-505054503030}" /success:enable /failure:enable

After the Audit is activated, running this PowerShell code will generate an output showing you blocked packets (if any).

For example, if you visit a website or access a server that is hosted in one of the countries you blocked, or a connection was made from one of those countries to your device, it will generate an event log that will be visible to you once you run this code.

#Requires -RunAsAdministrator
#Requires -Version 7.4
Function Get-BlockedPackets {
    Begin {
        [System.Diagnostics.Eventing.Reader.EventLogRecord[]]$Events = Get-WinEvent -FilterHashtable @{LogName = 'Security'; ID = 5152 }
        [System.Object[]]$Outputs = @()

        # Create an empty hashtable to store the firewall rule names and display names
        [System.Collections.Hashtable]$FirewallGroupPolicy = @{}

        # Loop through each firewall rule from the local policy store (for Firewall rules that are stored in Group Policy)
        foreach ($Rule in Get-NetFirewallRule -PolicyStore localhost) {
            # Add a new entry to the hashtable with the rule name as the key and the display name as the value
            $FirewallGroupPolicy[$Rule.name] = $Rule.DisplayName
        }

        # Loop through each local firewall rule (for Firewall rules that are defined locally in Windows Defender Firewall with Advanced Security)
        foreach ($Rule in Get-NetFirewallRule) {
            # Add a new entry to the hashtable with the rule name as the key and the display name as the value
            $FirewallGroupPolicy[$Rule.name] = $Rule.DisplayName
        }

        # Create a hashtable of partition numbers and their associated drive letters
        [System.Collections.Generic.Dictionary[string, string]]$DriveLetterMappings = @{}

        # Get all partitions and filter out the ones that don't have a drive letter and then add them to the hashtable with the partition number as the key and the drive letter as the value
        foreach ($Drive in (Get-Partition | Where-Object -FilterScript { $_.DriveLetter })) {
            $DriveLetterMappings[$Drive.PartitionNumber] = $Drive.DriveLetter
        }

        # Define the regex pattern for the device path
        [string]$Pattern = '\\Device\\HarddiskVolume(\d+)\\(.*)$'
    }
    Process {

        # Loop through each event in the $Events array
        foreach ($Event in $Events) {

            # Convert the event to an XML document
            $Xml = [System.Xml.XmlDocument]$Event.ToXml()

            # Pipe the data elements of the event to the next command
            $Xml.event.eventdata.data |

            # For each data element, do the following
            ForEach-Object -Begin {
                [System.Collections.Hashtable]$Hash = @{ TimeCreated = [System.DateTime]$Xml.Event.System.TimeCreated.SystemTime }
            } -Process {
                # Add the name and text of the data element as another key-value pair to the hashtable
                $Hash[$_.name] = $_.'#text'
            } -End {
                # Convert the hashtable to a custom object and pipe it to the next command
                [pscustomobject]$Hash
            } |
            # Filter out the objects that have a filter origin property matching any of the specified strings
            Where-Object -Property FilterOrigin -NotMatch 'Stealth|Unknown|Query User Default|WSH Default' | ForEach-Object -Process {

                # If the filter origin is in the hashtable keys
                if ($_.FilterOrigin -in $FirewallGroupPolicy.Keys) {
                    # Replace the filter origin with the display name of the firewall rule from the hashtable
                    $_.FilterOrigin = $FirewallGroupPolicy[$_.FilterOrigin]
                }

                # Create a hashtable with the protocol numbers and names
                [System.String]$ProtocolName = @{ 6 = 'TCP'; 17 = 'UDP' }[[System.Int32]$_.Protocol]

                # If the protocol number is not in the hashtable, keep it as it is, otherwise replace it with the protocol name
                $_.Protocol = if (-not $ProtocolName) { $_.Protocol } else { $ProtocolName }

                # If the direction is equal to '%%14592', set it to 'Outbound', otherwise set it to 'Inbound'
                $_.Direction = $_.Direction -eq '%%14592' ? 'Outbound' : 'Inbound'

                # If the application matches the pattern, replace the device path with the drive letter
                if ($_.Application -match $Pattern) {
                    [System.Int64]$HardDiskVolumeNumber = $Matches[1]
                    [System.String]$RemainingPath = $Matches[2]
                    [PSCustomObject]$GetLetter = $DriveLetterMappings[$HardDiskVolumeNumber]
                    [System.IO.FileInfo]$UsablePath = [System.IO.Path]::Combine("$GetLetter`:", $RemainingPath)
                    $_.Application = $_.Application -replace $Pattern, $UsablePath
                }

                # Add the modified object to the $Outputs array
                $Outputs += $_ | Select-Object -Property Application, SourcePort, Protocol, SourceAddress, DestPort, TimeCreated, Direction, DestAddress, ProcessId , FilterOrigin
            }
        }
    }
    End {
        Return $Outputs
    }
}
Get-BlockedPackets


How to Get Event Logs from the Miscellaneous Category in PowerShell

This code assumes you've already used the Harden Windows Security Module and the event logs custom views exist on your machine.

# Load the XML content from a file or a string
$xml = [xml](Get-Content -Path 'C:\ProgramData\Microsoft\Event Viewer\Views\Hardening Script\Exploit Protection Events.xml')

# Get the QueryList element using XPath
$queryList = $xml.SelectSingleNode("//QueryList")

# Convert the QueryList element to a string
$queryListString = $queryList.OuterXml

$Events = Get-WinEvent -FilterXml $queryListString -Oldest
$Events | Format-Table -AutoSize

C#


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