An engineer specialized in SPAM detection at Microsoft discovered a botnet that sends messages through Android devices.
As all other botnets that can infect PCs (as well as Macs), this one took over many devices running Google's OS to massively send spams.
Apparently, the devices were infected through hacked apps downloaded outside of Google's application Store. Therefore, it is not this time a malicious code that passed Google's not so rigorous screening. Given the way it infected these Android devices, it is very possible to find one day similar botnet on jailbroken iOS devices.
By Machmeter, original by Lionel