Find a malicious app I have a Google Nexus 5. 

Recently i had a problem about WI-FI, it just could not be turned on. I've found many suggestions how to fix that. None of them but turning on in safe mode solved the problem.

As i know, safe mode disables third party apps, which potentially can cause a problem.

I wonder how can i detect exactly which app caused wifi problem ?

What i think now is brute force approach, that is, to delete all the apps one by one and see what happens.
Do a brute force approach, but not by uninstalling apps one by one. Do it  in the  permission control. First go to settings, then go to permission control, then go to wifi and then uncheck app one by one . This may be woks