Mrs. Krebs and I were enjoying a relaxing, quiet morning last Saturday in our living room — silently bonding with our respective laptops propped on our knees — when she nearly jumped off of the sofa, shouting, “Uh oh! It’s one of those fake virus things popping up! WhatdoIdo!?!?” It occurred to me as I reached for her computer that most people probably wouldn’t know what to do should they stumble across a hacked or malicious site that tries to frighten and corral visitors into downloading and purchasing some rogue anti-virus product (a.k.a. “scareware”). The misleading pop-ups and animations about supposed security and privacy threats are unnerving, to be sure, and can be awfully convincing to the unwary. Typically, they are the result of scripts stitched into legitimate, hacked Web sites, or into banner ads that scam artists stealthily submit to some online ad networks. It is tempting to try