IN recent weeks, drivers on Route 7 near Minneapolis may have noticed something unusual: once a week, a painting crew has been hoisted up to repaint a section on the left side of a billboard, from green one week to red the next and finally to blue.

“Paint Drying,” says text on the billboard. “Admittedly more interesting than explaining malware prevention.”

The new advertising campaign, for Webroot, which makes antivirus software, also includes one billboard with a large swath of artificial turf attached meant to look like grass (“Grass growing. Admittedly more interesting than explaining spam filtration”), and another with a section of floorboards (“Laminate flooring. Admittedly more interesting than explaining spyware detection”).

The campaign, by TDA Advertising and Design in Boulder, Colo., is a departure for the computer security category, where marketers tend to either arouse fear, by promoting their products as a line of defense against identity theft or other mischief, or use jargon like phishing, keylogging and malware to strike a chord with those knowledgeable about computers.