How to remove macros from binary MS Office documents? - macros

Question

How can I programmatically remove macros from binary Microsoft Office documents (doc, xls, ppt)?
I do not want to do it for the XML format (xlsx, docx, pptx).
I do not want to disable macros in office, I really want to modify the file(s) and strip them of any macros.

Answer 1

This is assuming you want to automate the actual applications.
Add references to:
Microsoft.Office.Interop.Word
Microsoft.Office.Interop.Excel
Microsoft.Office.Interop.PowerPoint
Microsoft.Office.Interop.PowerPoint Microsoft Visual Basic for
Applications Extensibility Library
The following should get rid of your macro code for Excel. Automating Word and PowerPoint will be similar.
using Excel = Microsoft.Office.Interop.Excel;
using Word = Microsoft.Office.Interop.Word;
using PPT = Microsoft.Office.Interop.PowerPoint;
using Microsoft.Vbe.Interop;
namespace OfficeMacros
{
class Program
{
static void Main(string[] args)
{
}
static void RemoveMacrosExcel(string fileName, string newFileName)
{
var excel = new Excel.Application();
var workbook = excel.Workbooks.Open(fileName,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
foreach (VBComponent component in workbook.VBProject.VBComponents)
{
switch (component.Type)
{
case (vbext_ComponentType.vbext_ct_StdModule):
case (vbext_ComponentType.vbext_ct_MSForm):
case (vbext_ComponentType.vbext_ct_ClassModule):
workbook.VBProject.VBComponents.Remove(component);
break;
default:
component.CodeModule.DeleteLines(1, component.CodeModule.CountOfLines);
break;
}
}
workbook.Close(true, newFileName, Type.Missing);
// Release variables
workbook = null;
excel = null;
// Collect garbage
GC.Collect();
}
}
}
If you want to parse the binary file structures yourself, you will need to review these documents:
[MS-DOC]: Word (.doc) Binary File Format
[MS-XLS]: Excel Binary File Format (.xls) Structure Specification
[MS-PPT]: PowerPoint (.ppt) Binary File Format
If that seems too daunting, there is an excellent library created by DIaLOGIKa called b2xtranslator (Binary(doc,xls,ppt) to OpenXMLTranslator). It has most (if not all) of the binary structures for .doc, .xls, and .ppt mapped to C# objects.
While b2xtranslator's intention is to translate binary office documents to the newer OpenXML format, you could use the library to parse the documents and remove the macro elements yourself.