Excel Files Are Zipped Files

I do remember reading this before. I hadn’t realized what all got zipped up in those zip files.

Among other things, there is a file called calcChain.xml. This shows the order calculations are done on cells in the Excel spreadsheet.

That in turn can be used to figure out if cells have been moved around the sheet.

Data Colada has more information in their (very fascinating) post “[109] Data Falsificada (Part 1): ‘Clusterfake’“. It is dated June 17 2023 (and last accessed for this post on August 5 2023).

I have no idea if this is true of other spreadsheet types, like the LibreOffice Calc spreadsheets.