If you're looking for a Flappy Bird replacement, don't download any of the impostor apps from Android app stores. At least two security firms have confirmed that several fake Flappy Bird apps contain malware.

Security experts at Sophos discovered that a few different third-party apps available on Android apps stores are infected with malware. One of the fake Flappy Bird apps forces users to send a text message to a premium number before it lets you play the game. As soon as users send the text, their devices are exposed to malware attacks. Other impostor apps don't even both with this step and attack the unsuspecting downloader's device with malware almost immediately.

Trend Micro confirmed Sophos' report, stating that it has already found "a bunch of fake Android Flappy Bird apps spreading online." The security firm warned that nearly every fake Flappy Bird app it discovered "send[s] messages to premium numbers, thus causing unwanted changes to victims' phone billing statements." Many other versions simply infect the user's device with malware after the download is complete.

Trend Micro added that the majority of the dangerous apps are available in Russia and Vietnam's alternative Android app stores. These imitation apps are even more deadly because they claim that they are the real Flappy Bird app and don't ask users to register for a trial via text message.

These apps act exactly like the original app on the surface, but in the background, the imitation app is connecting to the Command and Control server via Google's Cloud Messaging. From there, the fake Flappy Bird apps send text messages without permission, hide notifications and give out the user's Gmail account information to anyone who wants to take it.

Although these types of attacks are nothing new on Android, the widespread popularity of Flappy Bird increases the likelihood that many users will download these fake apps and expose their devices to malware. In their desperation to discover a new Flappy Bird app, users can easily mistake impostor apps for the real deal.

Internet security experts advise Flappy Bird fans to find safe alternative apps instead of turning to black market imitation apps, which could infect their devices with malware. It would be wise to only download apps from the Google Play store because Google screens apps to make sure that they don't contain malware or other hidden dangers.

So, next time you go looking for a Flappy Bird back up, keep the old adage, "Buyer Beware," in mind.