Sounds like your router was compromised and was your initial point of entry. If you don't reset or replace it, the exploit will continue. From a device that is not compromised that is NOT connected to *your* wifi, change all your account passwords - email, Google, Samsung, Spectrum. Sign your phone out of Google and Samsung. Factory reset your phone, but do not set it up until you replace or reset your router and create a new SSID and wifi password. Do not forget to change the default password on the router (that's one eay they get in). After the router and new network is set up, then you can set up your phone again. Sorry this is happening to you, but this is not a Samsung issue.
