ESET Researchers found 35 Malicious Fake Android Apps in official Google Play Store that posed as security apps but it doesnt contain any of security future. A lot of these fake security apps are impersonating as security application and show malicious ads to generating revenue. These apps were installed over 6 Million times in the user devices and these apps are being under the radar for last few years. Among these 35 apps, only a handful stand out for their specific features: one app is not completely free as it offers a paid upgrade; one app has implemented a primitive, easily bypassed, app-locker manager.”]
Source: https://gbhackers.com/fake-android-apps-security-applications/

