Android is the platform most targeted by attackers. While security solutions have improved against such attacks on one side, attackers introduce new variants of existing malware by employing new strategies to evade them on another side. One of the most effective evasion techniques widely used is updating malicious code at runtime. Existing mobile security solutions are generally ineffective in detecting such attacks. The main objective of this project is to analyze updated attacks deeply, and to propose security solutions against such attacks by using static and dynamic analysis based detection techniques.