Windows Event ID 4885 – Security: Certificate Services Template Security Permissions Changed

Start by examining the specific details of the Event ID 4885 to understand what template permissions were modified and by whom.

1. Open Event Viewer on your Certificate Authority or domain controller
2. Navigate to Windows Logs → Security
3. Filter for Event ID 4885 using the filter option
4. Double-click the event to view detailed information including:
   • Template name that was modified
   • Security principal who made the change
   • Type of permission change
   • Timestamp of the modification
5. Note the Subject field showing who made the change and the Template Name field

Use PowerShell to query multiple events efficiently:

Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4885} -MaxEvents 50 | Format-Table TimeCreated, Id, LevelDisplayName, Message -Wrap

Check the current permissions on the affected certificate template to understand the impact of the changes.

1. Open Certificate Authority console on your CA server
2. Right-click the CA name and select Certificate Templates to Issue
3. Open Certificate Templates console (certtmpl.msc)
4. Right-click the affected template and select Properties
5. Click the Security tab to review current permissions
6. Document who has Read, Enroll, and Full Control permissions

Use PowerShell to audit template permissions programmatically:

Import-Module PSPKI
Get-CertificateTemplate | Where-Object {$_.Name -eq "TemplateName"} | Get-CertificateTemplateAcl | Format-Table Principal, AccessMask, AceType -AutoSize

Cross-reference Event ID 4885 with other security events to build a complete picture of the administrative session.

1. Search for related events in the same timeframe:
   • Event ID 4624 (Logon) for the user who made changes
   • Event ID 4634 (Logoff) to see session duration
   • Event ID 4648 (Explicit credential use) if alternate credentials were used
2. Use PowerShell to correlate events by user and timeframe:

$StartTime = (Get-Date).AddHours(-2)
$Events = Get-WinEvent -FilterHashtable @{LogName='Security'; StartTime=$StartTime} | Where-Object {$_.Id -in @(4624,4634,4648,4885)}
$Events | Sort-Object TimeCreated | Format-Table TimeCreated, Id, @{Name='User';Expression={$_.Properties[1].Value}}, @{Name='Details';Expression={$_.Message.Split("`n")[0]}}

3. Check Certificate Services operational logs for additional context:

Get-WinEvent -LogName "Microsoft-Windows-CertificateServicesClient-Lifecycle-System/Operational" -MaxEvents 20

Set up proactive monitoring to track future certificate template permission changes and detect unauthorized modifications.

1. Create a PowerShell script to monitor Event ID 4885:

# Save as Monitor-TemplatePermissions.ps1
$Query = @"

  
    *[System[EventID=4885]]
  

"@

Register-WmiEvent -Query "SELECT * FROM __InstanceCreationEvent WITHIN 10 WHERE TargetInstance ISA 'Win32_NTLogEvent' AND TargetInstance.EventCode = 4885" -Action {
    $Event = $Event.SourceEventArgs.NewEvent.TargetInstance
    Write-Host "Template permission change detected: $($Event.Message)" -ForegroundColor Yellow
    # Add email notification or logging here
}

2. Configure Windows Event Forwarding to centralize template permission events
3. Set up custom event log views in Event Viewer for quick access
4. Create scheduled tasks to export and archive template permission changes

If unauthorized template permission changes are detected, restore proper permissions from backup or known-good configurations.

1. Export current template permissions for comparison:

Import-Module PSPKI
$Template = Get-CertificateTemplate -Name "YourTemplateName"
$CurrentACL = Get-CertificateTemplateAcl -Template $Template
$CurrentACL | Export-Csv -Path "C:\Temp\CurrentTemplateACL.csv" -NoTypeInformation

2. If you have a known-good permission backup, restore it:

# Restore from previously exported ACL
$BackupACL = Import-Csv -Path "C:\Backup\TemplateACL-Baseline.csv"
foreach ($ACE in $BackupACL) {
    Set-CertificateTemplateAcl -Template $Template -Principal $ACE.Principal -AccessMask $ACE.AccessMask -AceType $ACE.AceType
}

3. Manually restore permissions through Certificate Templates console:
   • Open Certificate Templates console
   • Right-click affected template → Properties → Security
   • Remove unauthorized entries and restore proper permissions
   • Apply changes and verify in Event Viewer
4. Document the incident and update change management procedures