Hi,
If your device is not rooted there are simple ways to check out if your smartphone is infected and bring it back to normal. Please note that the problems you encounter are not necessarily coming from a malware infection and could be cause by your mobile provider, wrong settings or a broken update for example.
Here's what you should do:
1: that can seem obvious but have you tried to shut down and restart your phone ? This is the first thing to do if you encounter any kind of bugs or crash.
2: you need to make sure you won't lost your data. Make sure you're connected to your Google account and sync your settings (go to
this help page and down to "Manually sync your account" for an explanation on how to do so).
If your device is not connected already to your account or asks you to enter a password do NOT do it as of now, as a malware could steal your password (you can do it once you've proceeded step 3 and know your phone is clean). Don't forget to save your pictures as well. If you're lost and want to know more about how to sync your settings and save your data
this is an awesome tutorial.
3: go to Google Play and try and download some free malware removal tools. A scan with
Malwarebytes and
Bitdefender should detect most threats.
4: if you still have issues, you can try and clean temporary files with
CCleaner to see if that fix the problem.
5: if none of the above solved your problem, you should proceed with a master reset. This should solve any issues you have as it will set back your phone to factory settings.
Here's a useful tutorial on how to do so.
Don't forget to save your data as explained in step 2 as this will erase all your data and settings.
Let me know how it goes and good luck