Cyber criminals have already started creating malicious software programs for android devices. Last month, we reported about a new Ransomware that locks up the devices until the victims pay a ransom to get the keys to unlock the phone. But, the malware just lock the mobile screen and a loophole in the its implementation allowed users to recover their device and data stored on SDcard. The malware displays the following ransom message, written in Russian, which clearly means that this threat is targeting Russian Android users. After payment your device will be unlocked within 24 hours, and in case of no PAYMENT YOU WILL LOSE ALL data on your device!”
Source: https://thehackernews.com/2014/06/first-android-ransomware-that-encrypts.html