vba-extractor
Extract VBA/macro code from Microsoft Office files (.xlsm, .xlsb, .docm, .pptm). This skill should be used when users want to read, view, or extract VBA macros from Excel workbooks or other Office documents containing embedded VBA projects.
When & Why to Use This Skill
This Claude skill provides a streamlined way to extract and view VBA macro source code from various Microsoft Office formats, including .xlsm, .xlsb, .docm, and .pptm. By leveraging the specialized oletools library, it automates the decompression of binary VBA projects, allowing users to audit, document, or migrate legacy Office automation logic without needing to open the files in their native applications.
Use Cases
- Security Auditing: Safely inspect macro-enabled Office documents for potentially malicious code or unauthorized scripts without executing the file.
- Legacy System Migration: Extract complex VBA logic from old Excel or Word files to facilitate porting functionality to modern platforms like Python or web-based tools.
- Code Recovery: Retrieve lost or undocumented source code from legacy .xls or .doc files to maintain and update critical business workflows.
- Automated Documentation: Generate technical summaries and documentation for complex Excel-based tools by analyzing the underlying VBA modules and logic.
| name | vba-extractor |
|---|---|
| description | Extract VBA/macro code from Microsoft Office files (.xlsm, .xlsb, .docm, .pptm). This skill should be used when users want to read, view, or extract VBA macros from Excel workbooks or other Office documents containing embedded VBA projects. |
VBA Extractor
Extract and display VBA macro code from Microsoft Office files.
Overview
This skill enables extraction of VBA (Visual Basic for Applications) code from Office files with embedded macros. VBA code is stored in a compressed binary format inside Office files and requires specialized tools to extract.
Supported File Types
.xlsm- Excel Macro-Enabled Workbook.xlsb- Excel Binary Workbook.docm- Word Macro-Enabled Document.pptm- PowerPoint Macro-Enabled Presentation.xls- Legacy Excel files (97-2003).doc- Legacy Word files (97-2003)
Workflow
Step 1: Verify Python and oletools
The extraction requires Python with the oletools package:
python --version
pip install oletools
If oletools is not installed, install it first.
Step 2: Extract VBA Code
Run olevba with the -c flag to extract only the code (no analysis):
python -m oletools.olevba "<path-to-file>" -c > vba_code.txt
The -c flag outputs only the VBA source code without the security analysis.
Step 3: Read the Output
Read the generated vba_code.txt file to view the extracted VBA code.
Common Issues
Windows Encoding Errors
On Windows, the console may fail with Unicode encoding errors. To avoid this, always redirect output to a file:
python -m oletools.olevba "file.xlsm" -c > output.txt 2>nul
No VBA Project Found
If no VBA is found, the file may not contain macros or may be a different format (e.g., .xlsx instead of .xlsm).
Alternative Approaches (Not Recommended)
JavaScript libraries like cfb, xlsx, and ole-doc can read the VBA project structure but cannot reliably decompress the VBA source code. The Microsoft VBA compression algorithm is proprietary and these libraries lack proper decompression support.
What works: Python's oletools library
What doesn't work reliably: JavaScript-based extraction
Output Format
The extracted output includes:
- Module names (e.g.,
CropBoxes.bas,Sheet1.cls) - Full VBA source code for each module
- Separation markers between modules
Example output structure:
VBA MACRO ModuleName.bas
in file: xl/vbaProject.bin - OLE stream: 'VBA/ModuleName'
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Sub MySub()
' VBA code here
End Sub