0

Why is Excel warning me when opening a xlsx file? ("Warning, files from the internet can have viruses")

I thought that xlsx files cannot contain macros?

2 Answers 2

2

This is a general warning that Windows issues on the opening of any file of any type that was downloaded from the internet. It has no connection to the fact that the file is of type .xslx.

This is because security breaches have been found for almost all file types. Even if no such is currently known for .xslx files (or other), this doesn't mean that one won't be discovered tomorrow. Security is always one step behind the hackers.

3
  • ok, so basically one can trust a xlsx file ?
    – askolotl
    Nov 18, 2020 at 9:12
  • 3
    I recommend following this rule: One can trust any file from the internet if it comes from a trusted source. From all other sources, all file types should be suspect.
    – harrymc
    Nov 18, 2020 at 9:15
  • 2
    It's XLSM you need to be really careful of. Nov 18, 2020 at 9:29
1

Could also be because the file contains hyperlinks... that is if the warning comes direct from Excel and not Windows.

If you want to be super cautious, open the file first in google docs.

2
  • hi Mobus, what benefits to safety come from opening in google docs ? Welcome to Super User
    – PeterH
    Nov 18, 2020 at 10:27
  • Google docs running inside your browser would limit access to your local system files. Any vulnerabilities a potential virus would want to exploit would likely also be based on security flaws in MS office (if any) and wouldn't work or translate to google docs. Google docs will convert the excel file to its own format, keeping only the essentials and discarding office specific features, formatting, macros and well perhaps a sneaky virus. Nov 18, 2020 at 11:34

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .