If you have seen before annoying pop-up banners appearing in the right bottom side of your side, maybe you are victim of notifications of your browser. So, if you want to disable them it is quite easy, just open in your brower (chrome) and type the following url

chrome://settings/content/notifications

You will see allowed sites notifications and blocked sites. 

Just disable the sites you want to block 

How can you find an attachment in Gmail? 

It's very simple. Imagine you want to seek all email sent to This email address is being protected from spambots. You need JavaScript enabled to view it. with attachment.

So you need to introduce in gmail

to:This email address is being protected from spambots. You need JavaScript enabled to view it. has:attachment