For me I'd be looking at resetting Safari. While I can debate if this is an infection or not, add ons, extensions are ours to control. That said I'm encountering a lot of folk that just want to use a computer without dealing with its issues.
I think in this case I'd reset Safari as noted at http://www.macissues.com/2015/06/22/how-to-fully-reset-safari-on-your-mac/
No downloads required.
I am getting udm popup windows in the lower left corner of all safari windows. Adware/malware bad news.I don't see any activity in the Activity Monitor. I see removal info on the web, but it is all for Windows users. Do we have a udm removal solution for Macs, 10.7.5. Lion?