Facebook users are seeing a second search box on their Facebook interfaces. Facebook says it didn’t put the search box there and that it could be a sign of malware infection. It’s not clear whether the sinister search box is the result of an external malware exploit or a rogue Facebook application. Facebook members have access to a free, browser-based virus scanning tool from McAfee, according to the company. Facebook is in a constant battle against malicious hackers and online scammers who want to take advantage of its massive user base.”]