>Yes, as I mentioned in another message, it's a regular ZIP file with extension docx/xlsx.

Here is what I succeeded to do. From the first signature, which is 0h504B0304 for a Word 2007, with the exact number of bytes that I can get from the original file on disk, I can extract the file as is. However, I was able to do that because I had access to the file on disk. But, in our scenario, we do not have the original file on disk.