Get rid of ?? in the name of my downloaded file

[june]

I am downloading a file from a website for processing later. It is a text file. But after I downloaded the file it became a "document" file instead of plain text file. So my next step could not find any text file to process. When I use unix "ls" command I saw two "?"s appended, that is, xxxxx.txt?? I don't know where the "?"s came from and how to get rid of them. Please help!
test_http.kjb
renewable_http.kjb
renewable_get_yesterday_url.ktr