Webcake 3.0 malware

Recently one of my computers has been having searches highjacked by delta search.

 

So I did a full virus scan with Norton Internet security and it didn't find anything.

 

I then downloaded the free version of Malwarebytes and it found 56 malicious items

 

As well as delta-search it found something called webcake 3.0

 

I did a web search and found this http://virusremovalstation.blogspot.co.uk/2013/08/is-web-cake-30-malware-how-to-remove.html

 

This website claims that webcake steals bank details.

 

So my question is Why the hell didn't Norton stop this from getting on the system and why doesn't Norton pick it up when doing virus scans?

 

I'm actually disgusted that an anti-virus I paid for allowed something as bad as this to get on the computer.  If you pay for anti-virus you expect it to do it's job. Clearly Norton has failed.

 

So what is going on?

 

Why can't Norton detect this Malware?