Ignore the ads at the top of this page -- don't click on them:
http://filext.com/file-extension/udf

But do read the description at the bottom.

If you wanted, you could try opening the file in excel (File|open).

Or even copy the file and give it an extension that seems reasonable to try
(*.xls, *.xlsm, *.xlst, *.xlsb, .xla, *.xlam, ...)

Then try to open that copy of the file in excel.

I've never seen anyone use this extension for an excel file -- but there's
nothing wrong with trying to hide excel files with these kind of homemade
extensions.

Ruth wrote:

Hi

I have a file with a udf extension. When I searched the several sites said
that it was related to excel, so I opened it with excel. When opened, it is
incomprehensible letters and symbols. Is there a way to convert it so that
it is readabl?
--
Thank-you!
Ruth

--

Dave Peterson