There are many users and security experts all around the world that call PortaldoSites.com a virus or browser hijacker. When they mention this name, they report about annoying browser’s redirections and unwanted system’s changes. In fact, by doing that they mislead other people because this search engine has no malicious code inside. However, I can not argue that it’s a potentially malicious website.
PortaldoSites.com is closely related to browser hijacker, which, as soon as it infects the PC, modifies computer’s parameters and starts redirecting people to this site. Besides, it can also easily change the start page and default search engine to portaldosites.com or search.portaldosites.com. All users that have noticed these changes should have almost no doubts that their PC is infected with a browser hijacker. Its almost impossible to remove this virus manually, so you should run a full system scan without anti-spyware and remove malicious entries.