(Also lomonster.com and clomont.com)

Here is a brief explanation of the Excel 2007 formatting bug

PDF of analysis (500KB).

Zipfile of results and images (2.8MB) (contains PDF and images).

Large PNG of call graph (1.4 MB).


Excel 2007 contains a formatting bug, rendering 850*77.1 as 100000 instead of 65535. This was discovered around Sept 22, 2007.




Once this was making the rounds on the Internet, 12 values were found to format incorrectly.




I explain how this happens through disassembly and code analysis in the above PDF document.


Here is the faulty routine call graph. Click for a LARGE version.


Call Graph