Google and Apple recently removed hundreds of apps from their respective app stores after being informed they were actually fronts for gambling operations.
While it’s not unusual to find malicious apps, this operation was different in that many of the apps passed through Google and Apple’s vetting process, Trend Micro reported. This was accomplished by essentially delivering two apps in one to the app store reviewer, one good and one bad.
The “good” app presents itself and performs as advertised, delivering the weather, entertainment or fitness information, and tricking the reviewer into believing it is legitimate. However, once it is approved and uploaded to the store the malicious developers push through an update that alters the app content, bringing to the forefront the gambling app. In each case the code contained a switch that can turn the gambling function on or off.
“For example, before the app gets reviewed, the developer can simply press the off switch so a normal-looking app starts. The app could pass the app store reviews because the gambling aspect has been hidden. After the apps have passed the review, they can be publicly downloaded from the app stores. The threat actors then switch it on to enable viewing of the app’s actual content,” Trend Micro said in a report.
The apps have proven very popular, with some having been reviewed more than 400,000 times and ranking among the top 100 apps in the store.