Trying to install Adobe Flash, suddenly an intruder name Smart Search try to clean my mac computer, I stop

I need to remove something called Smart Search, my engine I use is Google, so if I try to open the computer immediately appears Smart Search and a box showing that is cleaning my browser, so I stop. The problem is that System preferences has been removed from dot menu, I trying to find it, it is no where, but stills on the menu bar, but cannot open it