Samsung galaxy 3. Internet opens on its own or play store.  After 3 months of using anti virus and scanning I have finally found the culprit.  CM ANTI VIRUS as well CM app lock or anything owned by CM like QuicPic.  Uninstall and you will no longer have the issue.  I have not had the issue since I uninstalled them all.  Even though CM antivirus was to be good for your phone IT ISNT!