It is a challenging task to surf the internet from various devices and also save your devices from virus attacks. Here is a malware called "Judy Malware" which has affected almost 3.65 cr android smartphones in the world. The most dangerous thing about the app is it spreads when you download the malacious app from one of the most secured store - Google Playstore !
According to Check Point, dozens of malicious apps have been downloaded nearly 4.5 million to 18.5 million times. Google has taken down the affected apps. Stay Safe ! 
Update -Google playstore will now gain its old reputation back. All the apps are completely safe from this Judy Malware now. Also checkout - Google PlayStore Free Apps.
What is Judy Malware ?
It is a malware that gets into the apps from Google Playstore. Once a phone is affected, advertisements will be shown in your phone and you will be forced to click on them. You click and the people behind this virus earn money ! Simple.
Should I Worry ?
Make sure you don't download untrusted applications in your phone from Google playstore for sometime. Its vulnerability is less than the Famous Wannacry Ransomware attack
If you are this much alert, trust me your are safe :) If your phone has been affected from this Malware, format your phone as soon as possible.
Why to Worry ?
But that does not mean that you don't have to worry about Judy Malware. The malware is very sophisticated, as evident by its design that can even defeat Google's Bouncer protection.
Currently it is not stealing Data from us. But the secret gateway it creates between an infected phone and the malware server it can possibly easily steal private details like credit card information and passwords from a phone.
These apps typically spanned the casual cooking and fashion games categories, under the “Judy” brand. Apps like Fashion Judy; Magic Girl Style and Fashion Judy; Masquerade Style are the home of Judy Malware
“Hackers can hide their apps’ real intentions or even manipulate users into leaving positive ratings, in some cases unknowingly.”
Stay Safe ! Don't Download apps from Unknown sources on Google Playstore for Sometime.