Every time I unlock my phone (yu yunicorn | marshmallow), ad pops up, covering the whole screen, ads also pop ups when I am using any app and it also uses chrome to direct to ads, its poping up when I am writing this, is there a way to stop these ads ?( disabling the internet is one way, I think, but I want to be connected all times)
These type of ads usually come from an app you have installed, typically uninstalling the offending app will correct this.
Use Addons Detector to determine the app that is causing the ads and uninstall it.
Install Dr. Web (You can use any antivirus but this worked for me) application from play store.
Let the application scan your mobile phone. It will detect and remove all the adware from you phone. I tried and this worked for me.