If you factory reset your device, all of the user data including photos, contacts etc will be deleted. You can sign back into Yahoo with your Yahoo email address and password. Viruses would be hypothetically deleted. Messenger and contacts will also be deleted.
I recommend backing up important data before performing factory reset.
This can be done by going to Settings > Accounts & Backup.
If you factory reset your device, all of the user data including photos, contacts etc will be deleted. You can sign back into Yahoo with your Yahoo email address and password. Viruses would be hypothetically deleted. Messenger and contacts will also be deleted.
I recommend backing up important data before performing factory reset.
This can be done by going to Settings > Accounts & Backup.
Your contacts will only be deleted if they are stored to your phone, not if the storage location is Google or your Sim card, but you should back them up anyway. You can check the storage location, by going into the contacts app (not the dialer tab) and clicking on the left menu bars and clicking on all contacts in the oblong window, it will being up a list of storage locations and you can see how many contacts are in which location. I would suggest going to manage contacts and merging and moving them into Google. That effectively creates a backup of your contacts that you can access from any device, anywhere. If you think you have a virus, do not restore your backup and ignore the invitation to do so when re setting up your phone. Upon reset, turn on the device's built in protection.
As a matter of fact, if you think you have a virus, turn the protection on now and run a scan. If the scan gets rid of any virus, you don't have to do the reset.
A reset does not delete or remove any virus or malware etc it will remain in memory as for the yahoo and rest you will just need to sign back in and add back your contacts etc
This is not correct. It is not possible for it to remain in memory after a reset. It would have to be a very sophisticated hack/piece of malware, since viruses are pieces of software code, and a factory reset erases the whole phone, including memory. Someone would have had to initiate code to embed itself into the hardware for it to remain on the phone/computer, etc.
As I said, it would have to be a sophisticated piece of malware, which most is not, depending on how it was picked up, and mostly applies to ransomware. Stop fearmongering.
