i guess you mean portaldosites.com search?
if so you have a browser hijacker, and the first program (AdwCleaner) in the guide Mikaelrask gave you should kill it
after you have run it, run the next program (Malwarebytes) also
post the logs here and tell us how it did go...
if still problems, continue with OTL and attach that log, then a removal expert will remove it for you later today