Windows Event ID 4793 – Microsoft-Windows-Security-Auditing: An attempt was made to call a privileged service

Start by examining the specific details of Event ID 4793 to understand the context and identify the requesting process.

1. Open Event Viewer by pressing Win + R, typing eventvwr.msc, and pressing Enter
2. Navigate to Windows Logs → Security
3. Filter for Event ID 4793 by right-clicking the Security log and selecting Filter Current Log
4. Enter 4793 in the Event IDs field and click OK
5. Double-click on a 4793 event to view detailed information including:
   • Subject Security ID and Account Name
   • Process ID and Process Name
   • Service Name and Privilege Name
   • Service Request Information
6. Note the timestamp, process details, and specific privilege being requested
7. Cross-reference the Process ID with Task Manager or Process Monitor if the process is still running

Use PowerShell to analyze Event ID 4793 patterns and identify trends or anomalies in privileged service calls.

1. Open PowerShell as Administrator
2. Query recent Event ID 4793 entries:

   Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4793} -MaxEvents 50 | Select-Object TimeCreated, Id, LevelDisplayName, Message

3. Filter events by specific time range:

   $StartTime = (Get-Date).AddDays(-7)
   $EndTime = Get-Date
   Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4793; StartTime=$StartTime; EndTime=$EndTime}

4. Extract and analyze process information:

   Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4793} -MaxEvents 100 | ForEach-Object {
       $xml = [xml]$_.ToXml()
       [PSCustomObject]@{
           TimeCreated = $_.TimeCreated
           ProcessName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'ProcessName'} | Select-Object -ExpandProperty '#text'
           ServiceName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'ServiceName'} | Select-Object -ExpandProperty '#text'
           PrivilegeName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'PrivilegeName'} | Select-Object -ExpandProperty '#text'
       }
   } | Group-Object ProcessName | Sort-Object Count -Descending

5. Export results for further analysis:

   Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4793} -MaxEvents 1000 | Export-Csv -Path "C:\Temp\Event4793_Analysis.csv" -NoTypeInformation

Fine-tune the audit policy configuration to control Event ID 4793 generation and ensure appropriate security monitoring coverage.

1. Open Local Security Policy by running secpol.msc as Administrator
2. Navigate to Advanced Audit Policy Configuration → System Audit Policies → Privilege Use
3. Double-click Audit Privilege Use and configure:
   • Check Configure the following audit events
   • Select Success to log successful privilege usage
   • Select Failure to log failed privilege attempts
4. Apply the policy and verify configuration with PowerShell:

   auditpol /get /subcategory:"Privilege Use"

5. For domain environments, configure via Group Policy:
   • Open Group Policy Management Console
   • Edit the appropriate GPO
   • Navigate to Computer Configuration → Policies → Windows Settings → Security Settings → Advanced Audit Policy Configuration
   • Configure the same Privilege Use settings
6. Test the configuration by performing a privileged operation and verifying Event ID 4793 generation
7. Monitor Security log size and configure appropriate retention policies:

   wevtutil gl Security

Investigate the broader context of Event ID 4793 by correlating with related system events and process activity.

1. Identify the Process ID from the Event ID 4793 details
2. Search for related events using the same Process ID:

   $ProcessID = "1234"  # Replace with actual PID from Event 4793
   Get-WinEvent -FilterHashtable @{LogName='Security'} | Where-Object {$_.Message -like "*Process ID: $ProcessID*"} | Select-Object TimeCreated, Id, Message

3. Check System log for service-related events:

   Get-WinEvent -FilterHashtable @{LogName='System'; Id=7034,7035,7036,7040} -MaxEvents 100 | Where-Object {$_.TimeCreated -gt (Get-Date).AddHours(-1)}

4. Use Process Monitor (ProcMon) to capture real-time process activity:
   • Download and run Process Monitor from Microsoft Sysinternals
   • Filter by the process name identified in Event ID 4793
   • Monitor file, registry, and network activity during privilege requests
5. Examine Windows Service dependencies:

   $ServiceName = "YourServiceName"  # From Event 4793
   Get-Service -Name $ServiceName | Select-Object -ExpandProperty ServicesDependedOn
   Get-Service -Name $ServiceName | Select-Object -ExpandProperty DependentServices

6. Review Application log for related errors or warnings:

   Get-WinEvent -FilterHashtable @{LogName='Application'; Level=2,3} -MaxEvents 50 | Where-Object {$_.TimeCreated -gt (Get-Date).AddMinutes(-30)}

7. Document findings and create a timeline of events for security analysis

Set up automated monitoring for Event ID 4793 to detect anomalous privileged service calls and potential security threats.

1. Create a custom Windows Event Forwarding subscription:

   <Subscription xmlns="http://schemas.microsoft.com/2006/03/windows/events/subscription">
       <SubscriptionId>Event4793Monitor</SubscriptionId>
       <SubscriptionType>SourceInitiated</SubscriptionType>
       <Query>
           <![CDATA[
           <QueryList>
               <Query Id="0">
                   <Select Path="Security">*[System[EventID=4793]]</Select>
               </Query>
           </QueryList>
           ]]>
       </Query>
   </Subscription>

2. Configure the subscription using wecutil:

   wecutil cs Event4793Monitor.xml

3. Create a PowerShell script for automated analysis:

   # Event4793Monitor.ps1
   $Events = Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4793; StartTime=(Get-Date).AddMinutes(-15)}
   foreach ($Event in $Events) {
       $xml = [xml]$Event.ToXml()
       $ProcessName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'ProcessName'} | Select-Object -ExpandProperty '#text'
       $ServiceName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'ServiceName'} | Select-Object -ExpandProperty '#text'
       
       # Define suspicious patterns
       $SuspiciousProcesses = @('powershell.exe', 'cmd.exe', 'wscript.exe', 'cscript.exe')
       
       if ($ProcessName -in $SuspiciousProcesses) {
           Write-Warning "Suspicious privileged service call detected: $ProcessName calling $ServiceName"
           # Send alert or log to SIEM
       }
   }

4. Schedule the monitoring script using Task Scheduler:

   $Action = New-ScheduledTaskAction -Execute 'PowerShell.exe' -Argument '-File C:\Scripts\Event4793Monitor.ps1'
   $Trigger = New-ScheduledTaskTrigger -Once -At (Get-Date) -RepetitionInterval (New-TimeSpan -Minutes 15) -RepetitionDuration (New-TimeSpan -Days 365)
   $Principal = New-ScheduledTaskPrincipal -UserId "SYSTEM" -LogonType ServiceAccount
   Register-ScheduledTask -TaskName "Event4793Monitor" -Action $Action -Trigger $Trigger -Principal $Principal

5. Configure Windows Event Log forwarding to SIEM or central logging system
6. Set up custom performance counters to track Event ID 4793 frequency:

   Get-Counter "\LogicalDisk(*)\% Free Space" -Continuous -SampleInterval 5

7. Test the monitoring system by generating test events and verifying alert functionality