Android smartphone platform has taken off like a rocket, winning more
than half the global smartphone market share only three years after it
was first introduced. But hitching a ride on that rocket are malware writers, who've been having a grand time exploiting the open-source, lightly supervised platform — especially in the past year.
Android's open model means anyone can create an app, and apps can be
installed from anywhere. But this has created an ideal delivery model
for cybercriminals, who inject Trojan horses — malware hidden inside
otherwise benign software — into legitimate-looking apps and put them on
the open market, often as free downloads.