Add DisplayName lookup from AD

Get-UserLastLogonComputer.ps1

@@ -6,7 +6,7 @@
 .DESCRIPTION
     Queries Domain Controller security event logs for logon events (4624)
     to determine which computer each user last authenticated from.
-    Resolves IP addresses to computer names for network logons.
+    Resolves IP addresses to computer names and looks up user display names.
 
 .PARAMETER OutputPath
     Path for the output CSV file. Defaults to current directory.
@@ -14,11 +14,11 @@
 .PARAMETER DaysBack
     Number of days of event logs to search. Default is 7.
 
-.PARAMETER IncludeNetworkLogons
-    Include Type 3 (Network) logons. Default is true.
+.PARAMETER ExcludeNetworkLogons
+    Exclude Type 3 (Network) logons. Default includes them.
 
-.PARAMETER ResolveIPs
-    Attempt to resolve IP addresses to hostnames. Default is true.
+.PARAMETER SkipIPResolve
+    Skip IP to hostname resolution. Faster but less useful.
 
 .EXAMPLE
     .\Get-UserLastLogonComputer.ps1
@@ -66,6 +66,8 @@ $StartDate = (Get-Date).AddDays(-$DaysBack)
 
 # Cache for IP to hostname resolution
 $IPCache = @{}
+# Cache for user display names
+$UserCache = @{}
 
 function Resolve-IPToHostname {
     param([string]$IP)
@@ -74,20 +76,16 @@ function Resolve-IPToHostname {
         return $null
     }
     
-    # Check cache first
     if ($IPCache.ContainsKey($IP)) {
         return $IPCache[$IP]
     }
     
     try {
-        # Try DNS reverse lookup
         $hostname = [System.Net.Dns]::GetHostEntry($IP).HostName
-        # Extract just the computer name (before the domain)
         $computerName = ($hostname -split '\.')[0].ToUpper()
         $IPCache[$IP] = $computerName
         return $computerName
     } catch {
-        # Try querying AD for the IP
         try {
             $computer = Get-ADComputer -Filter "IPv4Address -eq '$IP'" -Properties Name -ErrorAction SilentlyContinue
             if ($computer) {
@@ -101,6 +99,27 @@ function Resolve-IPToHostname {
     }
 }
 
+function Get-UserDisplayName {
+    param([string]$Username, [string]$Domain)
+    
+    $UserKey = "$Domain\$Username"
+    
+    if ($UserCache.ContainsKey($UserKey)) {
+        return $UserCache[$UserKey]
+    }
+    
+    try {
+        $User = Get-ADUser -Identity $Username -Properties DisplayName -ErrorAction SilentlyContinue
+        if ($User -and $User.DisplayName) {
+            $UserCache[$UserKey] = $User.DisplayName
+            return $User.DisplayName
+        }
+    } catch {}
+    
+    $UserCache[$UserKey] = ''
+    return ''
+}
+
 try {
     Write-Host "Retrieving logon events from Security log..." -ForegroundColor Yellow
     
@@ -128,7 +147,6 @@ try {
         
         $LogonType = [int]($xml.Event.EventData.Data | Where-Object { $_.Name -eq 'LogonType' }).'#text'
         
-        # Skip if not a logon type we want
         if ($LogonType -notin $LogonTypes) { continue }
         
         $Username = ($xml.Event.EventData.Data | Where-Object { $_.Name -eq 'TargetUserName' }).'#text'
@@ -143,7 +161,7 @@ try {
         if ($Domain -in @('Window Manager', 'Font Driver Host', 'NT AUTHORITY')) { continue }
         if ([string]::IsNullOrWhiteSpace($Username)) { continue }
 
-        # Determine computer name - try WorkstationName first, then resolve IP
+        # Determine computer name
         $Computer = $null
         if (-not [string]::IsNullOrWhiteSpace($Workstation) -and $Workstation -ne '-') {
             $Computer = $Workstation.ToUpper()
@@ -152,7 +170,6 @@ try {
         }
         
         if ([string]::IsNullOrWhiteSpace($Computer)) {
-            # Store IP if we couldn't resolve
             if (-not [string]::IsNullOrWhiteSpace($IPAddress) -and $IPAddress -ne '-') {
                 $Computer = "[$IPAddress]"
             } else {
@@ -168,6 +185,7 @@ try {
             $UserLogons[$UserKey] = [PSCustomObject]@{
                 Domain        = $Domain
                 Username      = $Username
+                DisplayName   = ''  # Will populate after
                 Computer      = $Computer
                 IPAddress     = if ($IPAddress -and $IPAddress -ne '-') { $IPAddress } else { '' }
                 LogonTime     = $LogonTime
@@ -183,6 +201,13 @@ try {
     }
 
     Write-Host "Processed $ProcessedCount matching logon events." -ForegroundColor Yellow
+    Write-Host "Looking up display names for $($UserLogons.Count) users..." -ForegroundColor Yellow
+
+    # Populate display names
+    foreach ($Key in $UserLogons.Keys) {
+        $User = $UserLogons[$Key]
+        $User.DisplayName = Get-UserDisplayName -Username $User.Username -Domain $User.Domain
+    }
 
     $Results = $UserLogons.Values | Sort-Object Domain, Username
 
@@ -192,7 +217,7 @@ try {
     }
 
     # Export to CSV
-    $Results | Select-Object Domain, Username, Computer, IPAddress, LogonTime, LogonType | 
+    $Results | Select-Object Domain, Username, DisplayName, Computer, IPAddress, LogonTime, LogonType | 
         Export-Csv -Path $CsvFile -NoTypeInformation -Encoding UTF8
 
     Write-Host "`n===== Results =====" -ForegroundColor Green
@@ -201,7 +226,7 @@ try {
     Write-Host ""
 
     # Display summary table
-    $Results | Format-Table Domain, Username, Computer, LogonTime, LogonType -AutoSize
+    $Results | Format-Table Domain, Username, DisplayName, Computer, LogonTime, LogonType -AutoSize
 
 } catch [System.Exception] {
     if ($_.Exception.Message -match "No events were found") {