Thousands of Android apps now include software that shoves marketing icons onto your phones start screen or pushes advertising into your notification bar. These ads come from different mobile marketing companies, all have the same goalto make money. Adware is a subcategory of Potentially Unwanted Programs (PUPs), which are apps or other types of software that you likely didnt want installed on your computer. So if you download a popular app that comes bundled with adware, you may be in for a less-than-pleasant experience.”]
Source: https://blog.malwarebytes.com/cybercrime/2017/10/mobile-menace-monday-despicable-adware/