Lookout: More Than a Million Android Users Downloaded Adware in the Past Year
Even if an Android user only downloads apps from Google Play, they could become infected with adware. Lookout estimates that 6.5 percent of free apps on Google Play contain adware, finding that it's most prevalent in personalization (26 percent), racing (23 percent), and sports games (18 percent) application categories.
In addition, Lookout says the global likelihood of a new Android Lookout user having adware on their device is 1.6 percent, which is relatively higher than other mobile threats, and 0.9 percent in the U.S.
What exactly constitutes adware in the first place? There really isn't a widely adopted set of guidelines, but as far as Lookout is concerned, adware is "an ad network that exhibits one or more of the following intrusive behaviors without requesting appropriate user consent: display advertising outside of the normal app experience, harvest unusual personally identifiable information, or perform unexpected actions as a response to ad clicks."