Phone hacked, or AT&T spoofed?

As of January 1st I moved to a new area and my AT&T account has started showing 2 or 3 calls a day *outgoing* to phone numbers in Miami, Atlanta, and Detroit. AT&T swears that the calls came from my phone and maybe they did, but I didn't make them, and they aren't in my phone's history.

Any ideas on how this happened? Is it possible that an app I installed could be making calls from my phone without displaying UI? Can someone spoof my SIM card? Also of note, my account is a family plan with three other phones. None of the other phone's accounts show any strange outgoing calls.

AT&T just credited my account a bunch of minutes, but that doesn't do anything to actually fix the problem. How do I fix this?


1.) Model Number ? Galaxy Nexus
2.) Firmware Version ? 4.2.1
3.) Baseband Version ? i9250XXLH1
4.) Kernel Version ? 3.0.31-gd5a18e0
5.) Build Number ? JOP40D

Also do you have a T-Mobile Data plan on your
PayAsYouGo or FlexPay Plan? AT&T data plan

Carrier ? unlocked, but using AT&T

Country you are using your phone in ? USA