When Apps Secretly Team Up to Steal Your Data

Pairs of Android apps installed on the same smartphone have ways of colluding to extract information about the phone’s user, which can be difficult to detect. Security researchers don’t have much trouble figuring out if a single app is gathering sensitive data and secretly sending it off to a server somewhere. But when two apps team up, neither may show definitive signs of thievery alone. And because of an enormous number of possible app combinations, testing for app collusions is a herculean task. A study released recently developed a new way to tackle this problem—and found more than 20,000 app pairings that leak data.