File type changed, can it be changed back?

[MasterMace]

I made a file using OpenOffice.calc (basically Excel). I saved it as a .xls file, then I opened the file using Excel on a borrowed laptop, and saved the file. Now I get a bunch of jarble when opening it in an older Excel or OpenOffice.calc. I checked the file type, and now it's different, but I'm not sure exactly what it says. See, it's still a .xls type, but has a little asian addition to the end of it

Can anybody figure out what this is?

More importantly, how do I change it back?

 

[MasterMace]

Seems like merely editing the file type back to plain old .xls isn't going to solve it, as it got converted.