evil.cs

unsafe {
    var machineCode = new byte[] { 0xc3 };

    var execMem = VirtualAlloc(
        IntPtr.Zero,
        new UIntPtr((uint)machineCode.Length),
        AllocationType.COMMIT | AllocationType.RESERVE,
        MemoryProtection.EXECUTE_READWRITE
    );

    Marshal.Copy(machineCode, 0, execMem, machineCode.Length);

    var f = (F)Marshal.GetDelegateForFunctionPointer(execMem, typeof(F));
    f(); // EVIL
}