Lockdown Lab #4 CRITICAL Windows Server

Rename and disable built-in Administrator

Rename and disable built-in Administrator

If you’re still running default Administrator accounts on your Windows Servers, you’re practically handing attackers a key. This isn’t theoretical; tools like Mimikatz and CrackMapExec prioritize RID 500, making it a prime target for lateral movement.

The built-in Administrator account has a critical flaw: it cannot be locked out. That means endless brute-force attempts. It also bypasses UAC, giving attackers an immediate leg up if they compromise it. This is basic hygiene, yet I still see it missed in many organizations.

The fix is simple and immediate: rename it, then disable it. Create a new, standard admin account for daily use.

Here’s the command for Windows Server: Rename-LocalUser -Name “Administrator” -NewName “scw_admin_disabled” Disable-LocalUser -Name “scw_admin_disabled”

Don’t leave this glaring vulnerability open. Tackle it today.

The fix

# PowerShell

Rename-LocalUser -Name "Administrator" -NewName "scw_admin_disabled"

Disable-LocalUser -Name "scw_admin_disabled"

Reference: CIS Windows Server Benchmark 2.3.1.1

Mark this as done

Open the interactive hardening checklist and tick this off in your environment.

Open interactive checklist →

Related Posts

Enable MFA for all users

If I had a nickel for every breach that started with a single compromised password, I'd have retired years ago. It's the oldest trick in...

lockdown-labhardeningazureidentity
/Shimi Cohen

Enable MFA on root account

Let's talk about the keys to the kingdom. Your AWS root account is exactly that – unrestricted access to everything, including billing. I've seen organizations...

lockdown-labhardeningawsidentity
/Shimi Cohen

Restrict who can create and publish Copilot Studio agents

Shadow IT is bad enough. Add generative AI, and you’ve got a recipe for serious data exfiltration. I’ve seen organizations completely miss this control. Any...

lockdown-labhardeningcopilot-studioservices
/Shimi Cohen