YT icon in filename

Please provide a screenshot to clarify the problem.

attached the screenshot which shows up in the editor along with filename

Did you remap this file to a different file type in Settings | Editor | File Types?

no. It only happened for a particular file name/ java class name.

Please provide a screenshot of the whole project view and the file view.

See http://stackoverflow.com/a/13374653/104891. Fix the mapping.