Try changing up your searches. Instead of searching for the full title just search for one or two words from the title and add the last name of the artist. A lot of it is just trial and error. There's no sure way of knowing if a file is fake or not. Just keep searching and change the keywords in your search. Fake files can be a real problem. Try searching at different times of the day, new hosts are always logging on and off so what you can't find now you may find later.
Try the suggestions in this thread:
Problems with the search How to find music (also tips for video)