Fake Instagram apps have been found stealing usernames and passwords for the social photo service. Malwarebytes found the apps, which claim to help users rack up followers, are well-rated and have been downloaded tens of thousands of times. The apps, called Followkade, LikeBegir and Aseman Security, specifically target Iranian users. After install, the apps open a page asking for Instagram credentials; they legitimately log the user into Instagram but also send the credentials to a malicious, attacker-controlled website.
Source: https://threatpost.com/fake-instagram-apps-google-play/143786/