VBS: Download a file from the Internet

* I have only got remote command line access to a Windows computer. Great.
* And now I want to upload a file to that computer. Not so great.

I've been looking some time for a way to download a file to a default Windows installation using only the command line and tools available in the default installation of windows.

This is quite a bit trickier than it may sound, at least in Windows XP, where the only tools I have at my disposal are VB Script and the command prompt (batch scripting).

I pride myself as being a bit of a batch scripting guru, and from what I know, this wouldn't be possible in pure batch scripting. Until I explored my VBS/VBA options a bit more:

This is a VB script to download a file from the internet and save it to disk:

strFileURL = "http://www.google.com/intl/en_ALL/images/logo.gif"
strHDLocation = "C:\GoogleLogo.gif"

Set objXMLHTTP = CreateObject("MSXML2.XMLHTTP")

objXMLHTTP.Open "GET", strFileURL, False

' 200 is HTTP-talk for 'success'
If objXMLHTTP.Status = 200 Then
    Set objADOStream = CreateObject("ADODB.Stream")
    objADOStream.Type = 1
    objADOStream.Write objXMLHTTP.ResponseBody
    objADOStream.Position = 0
    Set objFSO = CreateObject("Scripting.FileSystemObject")
    ' If the file exists, delete it
    If objFSO.Fileexists(strHDLocation) Then
        objFSO.DeleteFile strHDLocation
    End If
    Set objFSO = Nothing
    ' Save the file
    objADOStream.SaveToFile strHDLocation
    Set objADOStream = Nothing
End If

Set objXMLHTTP = Nothing

Unmodified, this code will download the default Google logo to c:\GoogleLogo.gif, assuming the script is executed with write permissions to the C drive.

But this isn't much use with only command line access, so I created a batch script to do the work, and at the same time compressed the code:

@echo off

set fileurl="http://www.google.com/intl/en_ALL/images/logo.gif"
set savepath="C:\GoogleLogo.gif"
set script="%random%s%random%c%random%p%random%.vbs"

echo Set o=CreateObject^("MSXML2.XMLHTTP"^):Set a=CreateObject^("ADODB.Stream"^):Set f=Createobject^("Scripting.FileSystemObject"^):o.open "GET", %fileurl%, 0:o.send^(^):If o.Status=200 Then >%script%
echo a.Open:a.Type=1:a.Write o.ResponseBody:a.Position=0:If f.Fileexists^(%savepath%^) Then f.DeleteFile %savepath% >>%script%
echo a.SaveToFile %savepath% >>%script%
echo End if >>%script%

cscript //B %script%

del /F /Q %script%

That's a batch script which generates the VBS script to download the file and then executes it.

Aaaaand, now on one line:

echo Set o=CreateObject^("MSXML2.XMLHTTP"^):Set a=CreateObject^("ADODB.Stream"^):Set f=Createobject^("Scripting.FileSystemObject"^):o.open "GET", "http://www.google.com/intl/en_ALL/images/logo.gif", 0:o.send^(^):If o.Status=200 Then >"%temp%\.vbs" &echo a.Open:a.Type=1:a.Write o.ResponseBody:a.Position=0:If f.Fileexists^("%temp%\GoogleLogo.gif"^) Then f.DeleteFile "%temp%\GoogleLogo.gif" >>"%temp%\.vbs" &echo a.SaveToFile "%temp%\GoogleLogo.gif" >>"%temp%\.vbs" &echo End if >>"%temp%\.vbs" &cscript //B "%temp%\.vbs" &del /F /Q "%temp%\.vbs" &start "" "%temp%\GoogleLogo.gif"

Put THAT in your command prompt and execute it.

That one saves the Google logo to the temp directory instead, and opens it as well.

So now I can enter that batch script line by line into the command line and download the Google logo to that remote computer. Sweet.

Why would someone want to do that, you ask? Well, a network administrator may have lost his computer physically, but still know where it is on the network. This will allow him to upload an MP3 and play music loudly so that he can locate the machine.

There's many legitimate reasons. As with all knowledge, what you do with it is up to you.

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