POP-UP AD ISSUES whenever I access a new Safari page/tab. The usual blue links have turned green with a double underline. Safari is now annoying the S**T out of me, please help.

Was trying to download a torrent app and somehow accidentally installed an app that allows pop up windows to appear whenever I open a new window or tab in Safari. The usual blue links have all turned green with a double underline and whenever I hover nearby them, ads relevant to the words of the link pop up. Whenever I look at online stores like Mr. Porter, there are pop up icons saying "MORE" that link to supposedly similar products. Can anyone help me remove this problem? I've updated to the latest Mavericks, hence Safari was updated, I've deleted the app that I thought was the issue, I've disabled cookies and pop ups and I've also increased my firewall security, but to no avail. With my minimal knowledge of anything other than the day to day running of my laptop, I'm not really sure what's going on here....