Security researchers warned Android users who were downloading fake Flappy Bird apps as it may install malware on devices that could lead to unwanted charges on their phone bills.

After its developer shuts down the game on Sunday, many users have turned to alternative app stores in downloading and installing the game. However, the game which has the same name, icon, and game mechanics is a fake one.

Security experts from Trend Micro and Sophos said that the satisfaction they may find in playing the fake Flappy Bird game may cost them much as installing the game may also install malicious software on their devices, The Sydney Morning Herald reported.

Sophos described the difference between a real Flappy Bird app and fake one. The real game only asked for network access so it can flash ads while the fake app asks for all sorts of permissions, such as the ability to send text messages, access other apps, build bookmarks, and many more.

Trend Micro, on the other hand, warned users that granting access to fake apps will automatically send text messages to premium numbers. These numbers offer services such as text alerts, news, mobile ringtones, videos, images, and etc. These are directly charged to the monthly bill of the users and they will not even know that the fake app is sending messages to the premium numbers.

To avoid such unwanted result, the best recommendation the security experts could give is to download and install apps and games only from trusted app stores like the Google Play.

Flappy Bird is a game that became a hit this January. It was developed by a Vietnamese game developer named Dong Nguyen and published by dotGEAR. However, because of the fame it has gotten from a lot of people, Nguyen has decided to pull out the game from Apple's App Store and Google's Play Store living only a brief notice in his Twitter account @dongatory saying, "I will take 'Flappy Bird' down. I cannot take this anymore."