A Trojan virus which has been developed for Android phones can create botnets(A botnet is a collection of software agents that run autonomously and automatically).
Trojan named Geinimi is the most sophisticated Android malware so far. Once it's installed on a user's phone, Geinimi can receive commands from a remote server that lets that server's owner control the smartphone. Geinimi is spreading through pirated versions of Android apps, games and is being distributed in third-party Android app stores in China.
When a smartphone user launches an infected application containing Geinimi, the Trojan collects information in the background. This information includes location coordinates and unique identifiers for the device and its SIM card. Every five minutes, the Trojan tries to connect to a remote server using one of 10 embedded domain names. These domain names include www.widifu.com; www.udaore.com; www.frijd.com; www.islpast.com and www.piajesj.com
Pirated applications that include the Trojan that are available in Chinese app stores include "Monkey Jump 2;" "Sex Positions;" "President vs. Aliens" "City Defense" and "Baseball Superstars 2010".
The original versions of these apps that are in the official Google Android Market have not been affected. So please download apps and games from Google official site :)