1. ActivityManager, http://developer.android.com/reference/android/app/ActivityManager.html
2. Androguard, http://code.google.com/p/androguard/
3. Android Malware Genome Project, http://www.malgenomeproject.org/
4. Intent, http://developer.android.com/reference/android/content/Intent.html
5. Malware that Takes Without Asking, http://labs.mwrinfosecurity.com/tools/2012/03/16/mercury/documentation/white-paper/malware-that-takes-without-asking/