Why do i get ads on my android homescreen

[AC Question]

Today i started to get ads on my android homescreen i'm using Nexus 4 running android 5.1.1 and i haven't installed any app recently,ads pop near google search widget and if i hold press on it it says Ads by google and theres and option to opt-out but it requires to download an third party application or using your IMEI,should i do a hard factory reset?

 

[B. Diddy]

Welcome to Android Central! At some point, you must have inadvertently installed adware, most likely along with some other app (probably a game). Try uninstalling your apps one by one until that goes away.

 

[Ridvan C]

First thank you for you fast answer,i've tried deleting every app that i've installed this month and sadly ads did not go away,i decided to backup and do factory reset and everything is fine now.
Again big thanks for fast answer

 

[Petros Syntelis]

I have the same problem. I get a popup ad bar on top of my home screen which hovers over all the apps i might open. I haven't installed any newo apps recently, but after the latest Android upgrade I got this. Of it caused by a random app upgrade I can't know which app is causing it. Any ideas?

 

[B. Diddy]

Welcome to Android Central! This is always tough to troubleshoot, because there's no easy way to tell which app the adware might have been associated with. Sometimes you just have to backup your data, then do a factory reset, as Ridvan C did.

 

[Ondrej Rosypal]

Hi, do you have by any chance an app called Premium Wallpapers HD installed?
If yes, get rid of it now as that is the culprit. Same thing happened to my wife yesterday and I spent hours searching for the solution. The app was sitting on her phone for more than a year and caused no issue but apparently, the developers have decided it was time to make some money and triggered the malware via silent update. I have already reported the app to Google, hopefully they will remove it from Play Store soon.

 

[Ridvan C]

Ondrej Rosypal,yes i did have that app it's kinda late because i did factory reset on my phone but it's good to know that this app may be the source of my problem,i won't download it .
Petros Syntelis,i just gave up i could not find the source of it and i did a factory reset,you might want to try what Ondrej said get rid of that app if you have it on your phone and if it does not help backup your stuff and do a factory reset,factory reset worked for me.

 

[Wormsworth]

Cross Posted from different topic=================

I have a similar problem on my Nexus 7 AOS 5.1.1 (after scanning this board, I find that different models of Android have the same problem - but this is the first one topic I saw). Seems to have started with AOS 5??

Random ads pop up between program launches/calls. If a program calls another program, or does some type of calling routine, the ad launches.
This is NOT related to any single program or browser, and does not launch every time (seems some time of time factor that controls it.)
A simple touch of the 'back' button and it closes, no reason to wait.

Is there some time of system logger app that will keep track of system call action? This would help to find the called/calling program.
A new problem has just started. Nexus 7 keeps rebooting it self (I have not localized the problem yet - too new) Seems to have something to do with streaming media - not sure yet.

Any ideas before I do a complete system reset. Rather not since some apps were installed on a limited time trial and can not be reinstalled. (app of the day - maybe the problem came from this app??)
System Reset would be a Royal Pain!!!
All my apps (but one) came from Google Play, and that one I know is clean.

W.