Help. Clearing browser cache not working on Passport, what do I do?

Last week, I clicked a link on a spam mail that I thought was legitimate opened up a website. I since then tried to clear it many times:
- Browser Settings > Privacy and Security > click "Clear History" and "Clear Cookies
It doesn't seem to work, if I start typing the first letter of this site name, the url shows up in the option bar.
I deleted all visited sites in history, all bookmarks but it still shows up.
Anyway I can get rid of it permanently?

When you type in the URL bar, it pops to the top of the screen and shows a magnifying glass on the left. Over on the right, it tells which search engine you're using. If yours is set to Google, then try going to google.com, start typing something in the search box and select Clear History. It might be the search engine you're using is saving the URL. For the other search engines, like Bing, you'll need to read up on how to clear their search histories.