  The fast growing market for smart phones coupled with their almost continuous
online presence makes these devices the new targets of virus writers. It has
been recently found that the topological spread of MMS (Multimedia Message
Services) viruses is highly restricted by the underlying fragmentation of the
call graph. In this paper, we study MMS viruses under another type of spreading
behavior: scanning. We find that hybrid MMS viruses including some level of
scanning are more dangerous to the mobile community than their standard
topological counterparts. However, the effectiveness of both scanning and
topological behaviors in MMS viruses can generally be limited by two
controlling methods: (i) decreasing susceptible handsets' market share (OS it
runs) and (ii) improving monitoring capacity to limit the frequency in which
MMS messages can be sent by the mobile viruses.
