VZW Galaxy Note 2 repeatedly getting MMS from stranger today with attachment that can't be opened?

[KiwiCoalBattery]

I have a very old Verizon Galaxy Note 2 that I keep in the car as a spare phone. It has a deactivated AT&T SIM card inside. I usually leave it off, but I turned it on and left it on yesterday.

This morning, the Note 2 started getting text message notifications which showed up in Hangouts. I've never used Hangouts, so I was puzzled. When I opened Hangouts, there were 11 messages and all of them have MMS attached. (but the app said something like the attachment could't be opened or downloaded) The sender is someone in 314 area code... when I Googled it, there's nothing about the number.

Like I said, this Verizon Note 2 has a deactivated AT&T SIM card inside, so it should not have been possible to send/receive text or voice calls at all. That made me even more confused.

I just got home and looked at the phone again. It is now on my home wifi network. I don't know what it's doing, but the wifi upload/download symbol on the top is going like crazy, like someone is uploading and downloading a bunch of stuff... but there are no open apps. Sync is disabled for everything on this phone... the Play Store is not allowed to auto update.... so I can't figure out what it's downloading/uploading...

any suggestions as to what's going on? Just to be safe, I yanked the back cover over and took the battery out.. until I can find out what's going on...
'
Thanks in advance!

 

[belodion]

Are you thinking of Stagefright?


Sent from my iPhone 5s using Tapatalk

 

[KiwiCoalBattery]

Are you thinking of Stagefright?


Sent from my iPhone 5s using Tapatalk

What's that? Is that an anti-virus app? I'll look into it... (EDIT: holy cow... I coudln't be more wrong... I just read and found out what this Stagefright thin is... do you think that's what I've got? )

I don't have any anti-virus on any of my phone... probably a bad idea? All the 4 computers/lap tops in my home are Macs, so I've never needed anti-virus... I thought Android also has no need for anti-virus.

The part that is creeping me out is that fact that it's getting the text message at all.... the deactivated AT&T SIM card is, well, deactivated, for at least several months. I only kept it in their because the Note 2 couldn't be used to dial 911 without a SIM card. (the Note 2 is kept in the car almost all the time as a spare)