Authors: Tsukasa Ooi
Tags: Android rootkit
Event: Black Hat Abu Dhabi 2011
Abstract: Android devices have been repeatedly hacked for root privileges. Sometimes by malware authors, and sometimes by users themselves. This is because if someone gains root privileges, he or she can gain control of the parts of the system which are most useful for attackers (and for users as well). But this is not the end of the story - we need a bit more knowledge to gain much privilege inside the Android application system. On the other hand, some Japanese Android smartphones have an extra Linux Security Module (LSM) to prevent these rooting issues and protect the system from being overwritten. But because of Android's security weaknesses and incomplete LSM protection, the Android application system can still be taken over by exploitation. This presentation explains what we can/cannot do if we gain root privileges on an Android device, and introduces a new kind of Android rootkit. This rootkit needs only root privileges (no kernel-mode, no ptrace) and bypasses all existing security modules. This fact implies the possibility of advanced Android malware.