Everytime an app gets insanely popular, vicious minds try to capitalize on the momentum -- and history suggests, Android is their most-targetted platform. So it wasn't really a big surprise when security researchers at Eset announced on Friday that at least three fake, possibly malicious Pokemon Go app have made it to Google Play, Android's marquee app store. From an Ars Technica report: Of the three, the one titled "Pokemon Go Ultimate" posed the biggest threat because it deliberately locks the screen of devices immediately after being installed. In many cases, restarting an infected phone isn't enough to unlock the screen. Infected phones can ultimately be unlocked either by removing the battery or by using the Android Device Manager. Once the screen has been unlocked and the device has restarted, the app -- which by now has the title PI Network --is removed from the device's app menu. Still, it continues to run in the background and surreptitiously clicks on ads in an attempt to generate revenue for its creators. Eset discovered two other fake Pokemon Go apps inhabiting Google Play, one named "Guide & Cheats for Pokemon Go" and the other "Install Pokemongo." Both deliver ads carrying fraudulent, scary-sounding messages that are designed to trick users into buying expensive, unnecessary services. One such message claims the device is infected with malware and prompts the user to spend money to get the malicious apps removed.