Download a file via HTTP from a script in Windows

This technique is very often used in hacking, download a file in memory using Powershell:

powershell -nop -c "& {(New-Object System.Net.WebClient).DownloadString('URL')}"

There's a utility (resides with CMD) on Windows which can be run from CMD (if you have write access):

set url=https://www.nsa.org/content/hl-images/2017/02/09/NSA.jpg
set file=file.jpg
certutil -urlcache -split -f %url% %file%

Cmdlets in Powershell:

$url = "https://www.nsa.org/content/hl-images/2017/02/09/NSA.jpg"
$file = "file.jpg"
$ProgressPreference = "SilentlyContinue";
Invoke-WebRequest -Uri $url -outfile $file

.Net under PowerShell:

$url = "https://www.nsa.org/content/hl-images/2017/02/09/NSA.jpg"
$file = "file.jpg"
# Add the necessary .NET assembly
Add-Type -AssemblyName System.Net.Http
# Create the HttpClient object
$client = New-Object -TypeName System.Net.Http.Httpclient
$task = $client.GetAsync($url)
$task.wait();
[io.file]::WriteAllBytes($file, $task.Result.Content.ReadAsByteArrayAsync().Result)

C# Command-line build with csc.exe:

https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/compiler-options/command-line-building-with-csc-exe

using System;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;

namespace DownloadImage
{
    class Program
    {
        static async Task Main(string[] args)
        {
            using var httpClient = new HttpClient();
            var url = "https://www.nsa.org/content/hl-images/2017/02/09/NSA.jpg";
            byte[] imageBytes = await httpClient.GetByteArrayAsync(url);
            using var fs = new FileStream("file.jpg", FileMode.Create);
            fs.Write(imageBytes, 0, imageBytes.Length);
        }
    }
}

Built in Windows applications. No need for external downloads.

Tested on Win 10

Since no one has pointed it out I would like to add my answer.

If you have a version of python installed you could use some external libraries to download files.

python -m pip install wget # install the library
python -m wget http://someserver.org/somefile.rar

Further on you could put this command in wget.bat file like this:

python -m wget %1

Then you could just run wget.bat from command line, but I prefer running it directly because it shows a nice progress bar when run directly.

Here's my attempt to resume the ways of how file can be downloaded on Windows without usage of external tools.

It includes BITSADMIN, Microsoft.XmlHTTP and WinHTTP with a hybrid batch/JScript script that does not need temporary files, and System.Net.WebClinet with JScript.NET self-compiled hybrid.

Copy and paste the following six lines (or just the last four lines) into a text file. Then rename it to vget.vbs.

'cscript vget.vbs >FILE.TXT
'Run this vbscript at command line. Use above syntax to download/create FILE.TXT
Set oX = CreateObject("Microsoft.XmlHTTP")
oX.Open "GET", "http://www.exampleURL.com/FILE.TXT", False
oX.Send ""
WScript.Echo oX.responseText

Obviously you need to customize three things in this script to make it work for you.

1. The part which says http://www.exampleURL.com/FILE.TXT. You will need to substitute the correct URL for the file you wish to download.
2. The command you will run at the command line to execute this script; will need to specify the correct name for the script, vget.vbs, if that is what you called it.
3. And the name FILE.TXT that you want the output to be directed to by a DOS batch command line.

I have only tried using this to download a raw ASCII text file (a more powerful CMD script) from my Dropbox account, so I don't know if it will work for EXE files, etc.; or from other Web servers.

If you dispense with the first two comment lines, it is only four lines long. If you know your way around VBScript you might even be able to carry this code around in your head, and type it into the command line as needed. It only contains five key command components: CreateObject, .Open, .Send, WScript.Echo and .responseText.

Try the System.Net.WebClient class. There is a sample PowerShell script at the bottom of this page:

$c = new-object system.net.WebClient
$r = new-object system.io.StreamReader $c.OpenRead("http://superuser.com")
echo $r.ReadToEnd()

I would use Background Intelligent Transfer Service (BITS) (primer):

Background Intelligent Transfer Service (BITS) is a component of modern Microsoft Windows operating systems that facilitates prioritized, throttled, and asynchronous transfer of files between machines using idle network bandwidth.

Starting with Windows 7, Microsoft advises to use the PowerShell cmdlets for BITS.

% import-module bitstransfer
% Start-BitsTransfer http://path/to/file C:Pathforlocalfile

You could also use BITS via COM Objects, see here for an example VBScript. And there is bitsadmin, a Command line tool to control downloads:

BITSAdmin is a command-line tool that you can use to create download or upload jobs and monitor their progress.

In Windows 7 bitsadmin.exe states itself that it is a deprecated tool. Nevertheless:

% bitsadmin.exe /transfer "NAME" http://path/to/file C:Pathforlocalfile