Research On Android Application Virtualization Protection Technology Based On LLVM

The development of mobile communication and smart terminal technology promotes the progress of social life,but also brings severe challenges to information security.Mobile operating systems and applications are facing unprecedented security threats.Therefore,mobile application security detection and protection technology research is becoming one of the hot issues in security research.At present,the security threats faced by Android applications mainly include static analysis,dynamic debugging,memory dump attacks,malicious code injection and repackaging attacks,etc.The characteristics of the Android system itself and the limitations of its security protection mechanism make the existing security protection method has been unable to effectively resist the above-mentioned attacks.In view of the shortcomings of current Android application protection methods,this paper proposes a method of Android Application Virtualization protection based on llvm(low level virtual machine).Based on the design of a hierarchical protection strategy for key functions of Android applications,code obfuscation and dynamic instruction mapping are implemented based on the LLVM platform,And then realize the virtualization protection of Android applications through a custom interpreter.The main research contents of this paper are as follows:(1)Designed an Android application function hierarchical protection strategy.According to the sensitivity of functions in Android applications and the impact of program virtualization on the performance of Android applications,a function hierarchical protection strategy is designed.According to the hierarchical protection strategy,select key functions to be added to the hierarchical protection list,which represents the function scale of virtualization protection.Through the hierarchical protection strategy,the execution speed of the Android application can be taken into account while the Android application is virtualized and protected.(2)A virtualization protection method for Android applications based on the LLVM platform is proposed.Nativeize key functions and generate LLVM intermediate representation IR,obfuscate the code for IR to improve program complexity,and then dynamically map the obfuscated IR instruction to a custom virtual instruction set,and complete the virtualization of Android applications through a custom interpreter Chemical protection.The privatization of virtual instructions and dynamic mapping rules will make it difficult for attackers to restore program logic through intercepted virtual instructions.(3)Designed and implemented an Android application virtualization protection system based on LLVM,which can realize function hierarchical protection,code obfuscation protection,command dynamic mapping and virtualization protection functions.Randomly select experimental samples to test the security,performance and compatibility of the system.Test result shows that the system can effectively improve the difficulty of reverse analysis by attackers and enhance the security of Android applications.