Google Chrome on GNU/Linux infected by extension
It is freeware (free as in "a filthy beer bottle with drowned insects inside") I removed this as soon as I identified it as the probable culprit -- and so far, no more Shopping Assistant.
The odd thing is that Shopping Assistant only activated upon visiting certain sites and, amazingly, a site for a local Indian Restaurant (India Jewel in Kenmore NY) seems to be one (hacked server?)