Unix executable files - is it a virus

This is nothing to worry about.

Mac OS X uses a number of techniques to associate a document with its application. One of them is the filename extension (e.g. .txt, .pdf, .jpg, etc.), but there are others.

If the document loses its association with the application it turns into a generic document and that's what you're seeing here (it's also possible someone changed the association, but that's less likely).

Since you're on a networked backup disk it's entirely possible that it's lost its association if the application isn't installed on the backup server.

The solution is simple - select the files and choose File -> Get Info. In the 'Open with' section of the Info window you can choose which application to open the document with. Choose the appropriate application and you're all set.

The easiest way to prevent this happening in the future is to save files with a filename extension. It's the lowest common denominator in file associations and therefore is least likely to run into problems.

Bruce,

If your network is connected to the internet, so is your network storage device, er, backup hard disk. Make sure that your network is properly configured and protected.

Scary devil icon? Would it resemble one of these beasties or is it more like this one?

Now for the good news: This is common for Quark files.
I googled the problem and here are some links that tell you how to fix the problem: Quark 3, Quark 6, a macfixit tip, and a macosx.com post.

Camelot's advice may not work, or may only work once. See the links for details.

Hope this helps.

-Wayne