Hello Allan !!! Hello Niel !!!
First of all thanks for your response.
Some info: I begun my Macs experience with a Performa 600 running 7.1 almost 20 yrs. ago. I can really say that
I enjoy the evolution through 8, 9 and OS X. Somehow I am aware that this pops-ups are scams.
What bothers me is that never happens before 3 or 4 days ago, now they are going on in all my browsers including Safari.
Almost all the time that I click a link in my bookmarks a MacKeeper page or any other pops-up first.
Something is wrong, and I want to fix it. I check securities, firewall, preferences for any single browser, etc etc.
Also I don't download anything out of the ordinary or open emails form unknown sources that can compromise my MBP.
Maybe I stream a movie sometimes from HBO.
Bottom line: something is not right.
Thanks for to all the invisible friends again !!!