Cyber thieves are tweaking tried-and-true computer viruses to work on Web-enabled smart phones. According to the research firm IDC, worldwide smart phone shipments topped 54 million in the first quarter of 2010, a 57 percent increase from the previous year. This fact has not escaped cybercriminals.

Users who mistakenly download a sham wallpaper app for the Google Android phone could get one that harvests the user's contacts and voicemail numbers, which can be used to pinpoint the user's location. Mobile security company Lookout uncovered 80 such Android Web apps in late July, which have since been removed by Google, according to Lookout CEO John Hering. The data was transmitted to a Chinese Web site. In this case, the wallpapers, reflecting innocent images of animals, basketballs and such, were downloaded more than 1 million times. "Smartphone usage is going mainstream," Hering says. "And so the bad guys are looking at Web browsing and the downloading of Web apps as two primary attack vectors."