The HippoSMS malware is a premium-rate SMS Trojan that sends costly SMS messages to premium-rated numbers. It also prevents users carriers from notifying them of the new charges. The malware is embedded in a seemingly legitimate Android app in the market, and once users download and install that app, the fun begins. Researchers at North Carolina State University came across the malware in some alternative Android markets in China. The Trojan is just the latest in a series of similar incidents in which attackers and scammers have inserted malicious apps or apps containing malware into app markets.
Source: https://threatpost.com/new-sms-trojan-targeting-android-users-071111/75414/