That link kinda sounds like the problem.. looks like I hit the wrong big download button.. I only recently started using Mumble rather than Ventrilo.. and Mumble v1.2.4 had given me issues with a greyed out 'Quit 'button, requiring force quitting the app every time.. so I was keen to get the update to v1.2.5 when Mumble prompted me.. but I had problems with the update link.
Frst couple of attempts the link just died.. then it appeared to do the install but left me with v1.2.4 still installed not v1.2.5.. so I manually went to Sourceforge and I must have hit the wrong download button.. but hey, that Genieo link is on the Sourceforge page with a big old download button, strategically placed!
As soon as it started running and flagged the name Genieo, I was suspicious.. but sometimes these Apps are made by companies with a different name to the software (this includes many WoW add-ons) however as soon as it mentioned 'alterations that might take 10 mins', I realised it was not Mumble being installed and immediately pulled the plug with a Force Quit on the installer.. made no difference, it quietly continued the install anyway, only annoucing the fact when it had finished (lesson learned, next time I will force power down the Mac).
Fairly sure I have now exterminated Genieo from the system, though.. thanks to advice on this site.