Okay, so the way I have the house set up is as follows. There's a computer upstairs that's a wired connection, via the cable modem and a wireless router. There is a wifi extender on the porch that connects to the wireless router and allows wifi coverage on the porch. There is a wireless adaptor on a computer downstairs that allows me to login to the wireless router upstairs. We routinely connect our phones to the wifi in order to avoid data usage.
I went to bed, still on wifi, but I don't recall which I was connected to, the house wifi or the extender. I wake up this morning, and have one of those notifications that says "open browser to finish connecting", like it does when you login to a hotel wifi and have to provide login info. This is already 100% out of the ordinary. I open the browser and it directs me to h.fb.com, and asks for login info. I give it nothing and look to find that I'm logged in to the extender. I try to connect to the house wifi. It won't connect. I open a browser window on the upstairs computer and it goes to my homepage, without incident. I bring up the router maintenance program on the computer, change the password, and try to log my phone in using the new password. Still no dice. It will only connect to the extender. So that gets unplugged right away, I'll deal with that when I get home and change its password. I check the router's client list, which should at the very least, show the upstairs computer via wired connection, the downstairs computer, and the wifi DVD player. The upstairs computer is the ONLY connected device. I try to login with the downstairs computer, using the new password. Still won't connect. I unplug the modem and the router for a minute or so. Plug those two back in, and everything is back to normal. I can connect to the upstairs wireless router.
So I've run several virus/malware programs on my phone, finding nothing. I've got virus scans running on BOTH computers at home and will check the results when I get there.
I'm a little shaken by this.