A surge of sites and apps are exhausting your CPU to mine cryptocurrency
The latest examples came on Monday with the revelation from antivirus provider Trend Micro that at least two Android apps with as many as 50,000 downloads from Google Play were recently caught putting crypto miners inside a hidden browser window. The miners caused phones running the apps to run JavaScript hosted on Coinhive.com, a site that harnesses the CPUs of millions of PCs to mine the Monero crypto currency. In turn, Coinhive gives participating sites a tiny cut of the relatively small proceeds. Google has since removed the apps, which were known as Recitiamo Santo Rosario Free and SafetyNet Wireless App.
https://arstechnica.com/information-technology/2017/10/a-surge-of-sites-and-apps-are-exhausting-your-cpu-to-mine-cryptocurrency/