Hi,

A friend of mine just sent me an ebook and in that ebook I found ebub file, what is this file. and how can I open it .. is it a virus came with pdf file my friend sent or it is something else ?

I think its a file related to the ebook then how I open it ? I am running windows 7 computer can I open it in it ?

Those are simply ebook format used by various ebook device like iphone and kindle . You can open them in windows 7 using software like STanza or if you use firefox then can install https://addons.mozilla.org/en-US/fir...on/epubreader/ .
You can also install windows version of mobi pocket reader.

I just noticed that you have named it eBub files but actually they are Epub files.