So a user comes to you and says their account has locked out and you kindly unlock their account…… 5 mins later they are contacting you again to unlock their account. Despite the standard troubleshooting steps the account continues to lockout. Now you have the task of finding out what is the reason for these lockouts. Users locking their accounts is a common problem, but if the reasons are not obvious then it can take some time to troubleshoot. The user could be logged into multiple devices (phone, computer, application and so on) and when they change their password it will cause an ongoing lockout issue. In this article, we will learn how to find out the source of account lockouts in Active Directory.
Using PowerShell to Find the Source of Account Lockouts
Step 1: Enabling Auditing to find the source of account lockouts
The first step we take is we need auditing turned in before the domain controllers will log any useful information. Every time a user gets locked out an event is created on the domain controller. With auditing turned on you will be able to capture these logs.
1. Open the Group Policy Management console. This can be from the domain controller or any computer that has the RSAT tools installed.
2. Modify the Default Domain Controllers Policy
Browse to the Default Domain Controllers Policy, right click and select edit.
3. Modify the Advanced Audit Policy Configuration
Browse to computer configuration -> Security Settings -> Advanced Audit Policy Configuration -> Audit Policies -> Account Management
Enable success and failure for the “Audit User Account Management” policy.
Auditing is now turned on and event 4740 will be logged in the security events logs when an account is locked out.
Step 2: Find the Domain Controller with the PDC Emulator Role
If you have a single domain controller (shame on you) then you can skip to the next step…hopefully you have at least two DCs.
The DC with the PDC emulator role will record every account lockout with an event ID of 4740.
To find the DC that has the PDCEmulator role run this PowerShell command
get-addomain | select PDCEmulator
Step 3: Finding event ID 4740 using PowerShell
All of the details you need is in event 4740. Now that you know which DC holds the pdcemulator role you can filter the logs for this event.
On the DC holding the PDCEmulator role open PowerShell and run this command
Get-WinEvent -FilterHashtable @{logname=’security’; id=4740}
This will search the security event logs for event ID 4740. If you have any account lockouts you should a list like below.
To display the details of these events and get the source of the lockout use this command.
Get-WinEvent -FilterHashtable @{logname=’security’; id=4740} | fl
This will display the caller computer name of the lockout. This is the source of the user account lockout.
You can also open the event log and filter the events for 4740
