At a site found these risks of ULTIMATE-SEARCH.NET virus, can I protect my Facebook by private browsing?

[Aden]

No, not really. The best way to protect yourself from viruses is to install an anti virus program like McAfee or Norton. Whenever you click on a link while browsing Facebook that redirects you to another Facebook page, don't enter your password it's a scam. You can verify you have a secure connection to a Facebook server by looking for the closed padlock symbol or noting the letter "s" in https in the address bar. Should you install a program, choose a custom installation. Uncheck all boxes that mention anything about toolbars, extensions and homepages. It's nothing but adware and in some cases can lead to trojans.