According to security researchers, reports made public on Friday, July 15, on Google Play are present several fake Pokemon Go apps that are harming for smartphones.

Ars Technica reports that one of these fake apps is the "Pokemon Go Ultimate" that requires Device Manager to be uninstalled or battery removal. Hackers are looking to capitalize on the ongoing Pokemon Go popularity by sneaking their fake apps into the official Google Play marketplace.

Security researchers from antivirus provider Eset report that they have found at least three such fake apps on Google Play. The biggest threat of the three is posed by the app titled "Pokemon Go Ultimate," because it immediately after being installed it deliberately locks the screen of devices.

In most cases, it is not enough to restart the infected phone to unlock the screen. Infected phones can ultimately be unlocked either by using the Android Device Manager or removing the battery.

The Pokemon Go Ultimate app is changing its title to PI Network, once the screen has been unlocked and the device has restarted. Even if the app is removed from the device's app menu, it will still continue to run in the background and click on ads in order to generate revenue for its creators.

Eset malware researcher Lukas Stefanko wrote that this is the first time when a lock screen functionality have been used successfully in a fake app present on Google Play. He added that this also poses the risk that the first lock screen ransomware makes its way on Google Play.

According to Gizmodo, the other two fake Pokemon Go apps discovered by Eset on Google Play are named "Guide & Cheats for Pokemon Go" and "Install Pokemongo." Both fake Pokemon Go apps deliver ads carrying fraudulent messages designed to trick users into buying unnecessary and expensive services. For instance, one such message prompts the user to spend money to remove a malicious apps claimed to be installed on the phone.