strange file

[Pammy]

I have an excel spreadsheet that all of a sudden looks like a bunch of
symbols and letters almost like some sort of text file but has the xls
extension. I do not know who did this. Is there a way to save it to bring
back my original excel spreadsheet?

 

[Gary''s Student]

Has the font changed?

 

[Pammy]

Not that I am aware, it looks like a bunch of garbarge, so I'm not sure if
someone tried to save it as something else.