Roll Around Adware / Malware

I thought I was quite anal about what I clicked on and installed, by somehow I've been infected by this horrible work of the devil!

If you didn't know; it inserts ads in google search and overlays webpages with adverts. It does this by collecting what you type and what you view, plus goodness knows what else. The collected stuff is sent to somewhere to be matched to adverts to send you.

NIS 21.6.0.32  did not prevent the infection, nor does it find it in the system.

Malwarebytes Anti-Malware 2.0.4.1028 does not detect it.

Anyone know how to get rid of it?