We are receiving many reports of disruptive ads on mobile phones and tablets that affect the use of the device and/or block content on the screen, even when no app is being used. Such ads could be an indicator of malicious software installed on your device. It may be a good idea to review the apps you have installed on the mobile device and delete anything that you do not recognize. At times, games and apps that look legitimate can cause disruptive ads, even when you are not using them.Apps for detecting pop-up ads on mobile devices, such as Addons Detector for Android, are often helpful for finding the app causing the problem. (This is just an example of the type of app that may be helpful and is not an endorsement or recommendation of this particular app.) Anti-malware apps, such as those listed in the following article, may also be helpful: https://www.tomsguide.com/us/best-antivirus,review-2588-7.html. (We do not endorse this third-party website or the apps reviewed there.) In addition, the device manufacturer, retailer, or your phone service provider may be able to help you troubleshoot these issues.