Security researcher Georgia Weidman was able to infect Android phones with her custom botnet. The Android botnet is dangerous because it communicates and spreads via SMS text messaging instead of Internet Internet access. The botnet can monitor and modify all data sent to and from the phone before you do, allowing the botmaster to command and control your phone without your knowledge. Don’t download apps or files from people you don’t trust, and be wary of any links or files embedded in text messages.”]
Source: https://www.csoonline.com/article/2127376/steps-to-secure-your-smartphone-against-data-theft.html