Your version is better, but you will see the other, too.

You are right that 'Please find the attached file' seems more logical grammatically. However, the other construction is an established formula that goes back a long time. Before the days of email attachments, we wrote letters saying 'Please find enclosed:...' , followed by what you were enclosing in the envelope. This formula works better if you have a number of items. 'Please find attached' is a kind of heading, followed by a list of attachments.

I don't have background on that

Hi! If you need help with spoken English, I'm glad to help you! I promise to go very slow and very patient! I am always looking for new friends all over the world! Please add me to Skype: jason_s1972 . Thanks and take care! :) -- Jason

Well, leaving words is confusing, sometimes.