a.akamaihd.net & Safari

Hi all. Last night I downloaded what I thought was a Flash plugin update (prompted by a legitimate site I visited) but it installed some kind of crazy 'Mac Cleaner' programme. I went through the usual process to delete and remove that but it left a strange search engine plugin on my browsers. I've removed it from Chrome & Firefox (which was easy) run a virus cleaner but it's still messing with Safari.

I've wiped Safari but when I go to preferences it still shows that my set homepage is http://search46107304-a.akamaihd.net/h?_pg=D7634BD9-F8A9-54E1-8E63-775A46B626FA

I've tried setting a new homepage (BBC News, Google, whatever) but, no matter what I do, it defaults to the above. I have no plugins installed and I just don't know what to do to either kill the malware completely or how to fix Safari. I even reinstalled MacOS and it's still doing it.

Anyhow, anyone got any ideas?