Nine out of every thousand smartphones in the U.S. likely have annoying or dangerous ad software installed on the device, according to an analysis out Wednesday by mobile security provider Lookout. The company said its report is the first one to break down the existence of malicious software in phones by country.
"The key takeaway for average users is that while their chances of encountering a mobile threat are relatively low, they can protect themselves by understanding what types of threats are more prevalent in their area," said Jeremy Linden, Lookout's security product manager.
About 56% of American adults own a smartphone, according to a Pew Research survey also released Wednesday. Their biggest security worry is the advertising software, or adware, that sometimes comes bundled in apps such as games. It often contributes to poor battery life and might lead to strange pop-ups, toolbars or icons.
Linden said adware is commonplace in the Google Play store.
"If you download an app from Google Play, look at who's publishing it," he said. "Are they reputable or a fly-by-night company?"
About two in every thousand smartphone users is affected by apps that surreptitiously track their location, an issue that's much more pressing in the U.S. than other countries.
"In the U.S., surveillanceware or spyware operates in a quasi-legal area," Linden said. "It may be legal for me to install spyware on my wife's phone because it's community property."
Linden said having a password on a phone might be the strongest measure to counteract the installation of surveillance tools.
Two in every thousand users are also susceptible to having financial accounts hacked by apps silently operating in the backgrounds. Known as a Trojan, this form of malware is typically installed when a user downloads an app from somewhere other than Google Play.
"In general, they're exhibiting poor user behavior," Linden said of people who ended up with a Trojan on their phone.
Apps that automatically charge to cellphone bills with minimal notice -- called chargeware -- aren't as common in the U.S. as elsewhere. Typically, these apps give a user access to pornography.
Overall, smartphone users in India are three times more likely than those in the U.S. to come across one of these threats, according to Lookout. German and British users face a slightly larger threat than those in the U.S., while people in Japan were half as likely to encounter something malicious.
"This is what we've known anecdotally," Linden said. "Emerging markets tend to be more of a Wild West."
The company's data came from looking at detections made by its mobile security app on the phones of new users between January and mid-May. Lookout also suggested that users disable USB debugging in their settings, double-check URLs before entering in sensitive information, keep apps updated and be alert for unusual text messages and strange charges.