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Event ID 4865InformationMicrosoft-Windows-Security-AuditingWindows

Windows Event ID 4865 – Microsoft-Windows-Security-Auditing: A trusted logon process has been assigned to an authentication package

Event ID 4865 records when Windows assigns a trusted logon process to an authentication package, typically during system startup or security subsystem initialization.

Emanuel DE ALMEIDAEmanuel DE ALMEIDA
18 March 20269 min read 0
Event ID 4865Microsoft-Windows-Security-Auditing 5 methods 9 min
Event Reference

What This Event Means

Event ID 4865 represents a fundamental security architecture event in Windows authentication systems. When the Local Security Authority Subsystem Service (LSASS) assigns a trusted logon process to an authentication package, it creates an audit trail that security professionals rely on for compliance and threat detection.

The trusted logon process assignment mechanism ensures that only authorized components can handle sensitive authentication operations. Windows maintains strict control over which processes can interact with authentication packages like Kerberos, NTLM, and custom authentication providers. This event fires whenever the system establishes or modifies these trust relationships.

In enterprise environments, this event becomes particularly important when organizations deploy custom authentication solutions, smart card authentication, or third-party identity management systems. Each authentication package assignment represents a potential attack vector that threat actors might exploit to bypass authentication controls or escalate privileges.

The event structure includes the logon process name, authentication package identifier, and security context information. Modern Windows versions generate this event more frequently due to enhanced security features like Windows Hello, biometric authentication, and cloud-based identity integration that require dynamic authentication package management.

Applies to

Windows 10Windows 11Windows Server 2019/2022/2025
Analysis

Possible Causes

  • System startup and winlogon.exe initialization
  • Third-party authentication provider installation or loading
  • Security policy changes affecting authentication packages
  • Smart card or biometric authentication system activation
  • Custom authentication package registration
  • Windows Hello or PIN authentication setup
  • Domain controller authentication service initialization
  • Group Policy changes modifying authentication settings
  • Security subsystem restart or recovery operations
Resolution Methods

Troubleshooting Steps

01

Review Event Details in Event Viewer

Start by examining the specific event details to understand which logon process and authentication package are involved.

  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 4865 by right-clicking the Security log and selecting Filter Current Log
  4. Enter 4865 in the Event IDs field and click OK
  5. Double-click on a recent Event ID 4865 entry to view details
  6. Review the General tab for logon process name and authentication package information
  7. Check the Details tab for additional XML data including security identifiers
Pro tip: Look for the LogonProcessName and AuthenticationPackageName fields in the event details to identify which components are being assigned.
02

Query Events with PowerShell

Use PowerShell to retrieve and analyze Event ID 4865 occurrences with filtering capabilities.

  1. Open PowerShell as Administrator
  2. Query recent Event ID 4865 entries:
    Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4865} -MaxEvents 50 | Format-Table TimeCreated, Id, LevelDisplayName, Message -Wrap
  3. Extract specific event properties:
    Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4865} -MaxEvents 10 | ForEach-Object {
    [xml]$xml = $_.ToXml()
    [PSCustomObject]@{
        TimeCreated = $_.TimeCreated
        LogonProcessName = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'LogonProcessName'} | Select-Object -ExpandProperty '#text'
        AuthenticationPackage = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'AuthenticationPackageName'} | Select-Object -ExpandProperty '#text'
        SubjectUserSid = $xml.Event.EventData.Data | Where-Object {$_.Name -eq 'SubjectUserSid'} | Select-Object -ExpandProperty '#text'
    }
}
  4. Filter events by date range:
    $StartTime = (Get-Date).AddDays(-7)
$EndTime = Get-Date
Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4865; StartTime=$StartTime; EndTime=$EndTime}
Warning: Large Security logs may cause performance issues. Use -MaxEvents parameter to limit results.
03

Analyze Authentication Package Registry Settings

Examine the registry to understand which authentication packages are configured and their trust relationships.

  1. Open Registry Editor by pressing Win + R, typing regedit, and pressing Enter
  2. Navigate to the authentication packages registry key:
    HKLM\SYSTEM\CurrentControlSet\Control\Lsa
  3. Review the Authentication Packages value to see configured packages
  4. Check the Security Packages value for additional security providers
  5. Examine notification packages:
    HKLM\SYSTEM\CurrentControlSet\Control\Lsa\Notification Packages
  6. Use PowerShell to query registry values programmatically:
    Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" -Name "Authentication Packages"
Get-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" -Name "Security Packages"
  7. Compare current settings with baseline configurations to identify unauthorized changes
Pro tip: Document baseline authentication package configurations during system deployment to detect unauthorized modifications.
04

Monitor Authentication Package Loading with Process Monitor

Use Process Monitor to track real-time authentication package loading and identify the processes responsible for Event ID 4865.

  1. Download and run Process Monitor (ProcMon) from Microsoft Sysinternals
  2. Configure filters to monitor LSASS.exe activity:
    • Set Process Name filter to lsass.exe
    • Set Operation filter to Process and Thread Activity
  3. Clear existing events and start monitoring
  4. Trigger authentication package loading by:
    • Restarting the system
    • Installing authentication software
    • Changing security policies
  5. Correlate Process Monitor events with Event ID 4865 timestamps
  6. Examine the call stack and loaded modules in LSASS.exe
  7. Use PowerShell to cross-reference with security events:
    $ProcMonTime = Get-Date "2026-03-18 10:30:00"
Get-WinEvent -FilterHashtable @{LogName='Security'; Id=4865; StartTime=$ProcMonTime.AddMinutes(-5); EndTime=$ProcMonTime.AddMinutes(5)}
Warning: Process Monitor generates large amounts of data. Use specific filters to avoid performance impact.
05

Advanced Security Auditing and Correlation Analysis

Implement comprehensive monitoring to correlate Event ID 4865 with other security events for threat detection and compliance reporting.

  1. Enable advanced security auditing policies:
    auditpol /set /subcategory:"Other Logon/Logoff Events" /success:enable /failure:enable
auditpol /set /subcategory:"Security System Extension" /success:enable /failure:enable
  2. Create a PowerShell script for correlation analysis:
    $Events = Get-WinEvent -FilterHashtable @{LogName='Security'; Id=@(4865,4624,4648,4768)} -MaxEvents 1000
$GroupedEvents = $Events | Group-Object {$_.TimeCreated.ToString("yyyy-MM-dd HH:mm")} | Where-Object {$_.Count -gt 1}
$GroupedEvents | ForEach-Object {
    Write-Host "Time: $($_.Name)"
    $_.Group | Format-Table Id, LevelDisplayName, Message -Wrap
}
  3. Set up Windows Event Forwarding (WEF) for centralized monitoring:
    • Configure source computers with winrm quickconfig
    • Create custom event subscription XML
    • Deploy subscription to collector server
  4. Implement SIEM integration using Windows Event Log API:
    $Query = "*[System[EventID=4865]]"
$Events = Get-WinEvent -FilterXPath $Query -MaxEvents 100
$Events | ConvertTo-Json -Depth 3 | Out-File "C:\Logs\Event4865_Export.json"
  5. Create automated alerting for suspicious authentication package assignments
  6. Establish baseline behavior patterns and implement anomaly detection
Pro tip: Correlate Event ID 4865 with Event IDs 4624 (successful logon) and 4648 (explicit credential logon) to identify authentication flow patterns.

Overview

Event ID 4865 fires when the Windows Local Security Authority (LSA) assigns a trusted logon process to an authentication package. This event occurs during system startup, security subsystem initialization, or when authentication packages are dynamically loaded. The event captures critical security architecture changes that affect how Windows handles authentication requests.

This event appears in the Security log and provides visibility into the authentication infrastructure. Each trusted logon process represents a component authorized to handle authentication operations on behalf of the operating system. Common triggers include winlogon.exe initialization, third-party authentication providers loading, and security policy changes that affect authentication packages.

The event contains details about the logon process name, authentication package, and the security context under which the assignment occurred. System administrators use this event to track authentication infrastructure changes and investigate potential security policy violations or unauthorized authentication package modifications.

Frequently Asked Questions

What does Event ID 4865 mean and when does it occur?+
Event ID 4865 indicates that Windows has assigned a trusted logon process to an authentication package. This occurs during system startup when winlogon.exe initializes, when third-party authentication providers load, or when security policies change. The event represents a normal part of Windows authentication infrastructure initialization but provides important security audit information about which processes are authorized to handle authentication operations.
Is Event ID 4865 a security concern or normal system behavior?+
Event ID 4865 is typically normal system behavior, but it requires monitoring in security-conscious environments. While the event itself indicates legitimate authentication package assignment, unauthorized or unexpected authentication packages could represent security risks. Monitor for unusual logon process names, unknown authentication packages, or events occurring outside normal system startup times. Establish baselines to identify deviations that might indicate malicious activity or policy violations.
How can I identify which authentication packages are legitimate on my system?+
Legitimate authentication packages include standard Windows components like Kerberos (kerberos.dll), NTLM (msv1_0.dll), and Negotiate (negotiate.dll). Check the registry at HKLM\SYSTEM\CurrentControlSet\Control\Lsa for configured packages. Compare current configurations with documented baselines and vendor documentation for third-party software. Use PowerShell to query package details and verify digital signatures. Suspicious packages often lack proper signatures or appear in unexpected locations.
What should I do if I see unexpected Event ID 4865 entries?+
First, identify the logon process name and authentication package from the event details. Research whether the package corresponds to recently installed software or system updates. Check if the timing correlates with legitimate administrative activities. Verify the digital signature and file location of the authentication package. If the package is unrecognized, isolate the system, run antimalware scans, and review recent system changes. Consider restoring from a known-good backup if malicious activity is confirmed.
How do I configure monitoring and alerting for Event ID 4865?+
Enable Security auditing for 'Other Logon/Logoff Events' using auditpol or Group Policy. Use Windows Event Forwarding to centralize events from multiple systems. Create PowerShell scripts or SIEM rules to filter for unusual authentication package names or timing patterns. Set up automated alerts for events occurring outside maintenance windows or containing unrecognized package names. Implement correlation rules that trigger when Event ID 4865 appears with other suspicious authentication events like failed logons or privilege escalation attempts.
Documentation

References (2)

1
Microsoft Security Auditing Events DocumentationComprehensive guide to Windows security auditing events and their meaningshttps://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/security-auditing-overview
2
Windows Authentication ArchitectureTechnical overview of Windows authentication components and processeshttps://docs.microsoft.com/en-us/windows-server/security/windows-authentication/windows-authentication-architecture
Emanuel DE ALMEIDA
Written by

Emanuel DE ALMEIDA

Senior IT Journalist & Cloud Architect

Microsoft MCSA-certified Cloud Architect | Fortinet-focused. I modernize cloud, hybrid & on-prem infrastructure for reliability, security, performance and cost control - sharing field-tested ops & troubleshooting.

Tags
#event-id-4865#windows-security#authentication-auditing

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