How can you find out if .xlsx and .docx files are safe to open?

Question

I have received an email from a not entirely trustworthy source, it might be legit but I'm not really sure. It contains, among other things, information on a `.docx` Microsoft Word file and a `.xlsx` Microsoft Excel file.I have already scanned the files on http://virustotal.com and no viruses have been found, but I also read that macros can exist in the xml or zipped portion of the files themselves. I am seeking ideas about pinpointing potential malicious intent, such as finding macros.

Answer 1

If your purpose is to simply review the data/ contents I'd suggest opening the document via Google Docs and then exporting it to a fresh file which you can then open and review. Otherwise if you want to maintain the Excel file's integrity you'll want to first verify that your Excel security settings under 'Options' and 'Trust Center' are set to disable macros and ActiveX.