I was a victim of this last October and November on a T-Mobile number. This is what occurred:
- My Gmail account was compromised
- My Amazon account was compromised
In Gmail, they added a filter to hide any shipping or customer service messages from Amazon.
In Amazon, every other day, they placed an order for a ~500 USD GoPro device, delivered to an address in NYC. This address changed with every order.
Both passwords to both accounts were kept the same.
After I caught on to the above once I received my credit card statement, in November:
- They attempted to purchase something with my credit card. Security mechanisms triggered, and a verification code was sent to my phone at 4am in the morning. They successfully validated and placed the order. My credit card company assures me they input the right verification code.
- They applied for an Amazon credit card using my identity. It was auto approved, and they used the credit card to purchase ~5k worth of items.
I moved everything off of that T-Mobile number, and switched over to GoogleFi (only to learn GoogleFi uses T-Mobile also... still better than T-Mobile directly I'm hoping).
Edit:
I also wiped my phone, eventually thought that wasn't far enough, and switched to a new device entirely. I'm still unsure how the above occurred, because some of it feels beyond the scope of a SIM-swap.