"At its simplest, the main Simjacker attack involves a SMS containing a specific type of spyware-like code being sent to a mobile phone, which then instructs the UICC (SIM Card) within the phone to ‘take over’ the mobile phone , in order to retrieve and perform sensitive commands."
Not this again...
That spyware SMS is just a set of commands the phone recognizes and apart from open browser it is not able to do anything interesting.
Location? Who cares? Play tone? That at least could be annoying.
AdaptiveMobile said it has seen the S@T Browser technology active on the network of mobile operators in at least 30 countries around the globe. These countries, researchers said, have a cumulative population of over one billion, all of whom are exposed to this silent surveillance method. According to a source who spoke with ZDNet, the impacted countries are in the MENA (Middle East North Africa) region, and a few in Asia and Eastern Europe.
So, unless you're in a 3rd world country with ancient technology you don't need to panic and run to the hills.
It also seems like most US carriers are unaffected.
All
Also:
ZDNet states that this theoretical attack tactic was known back in 2011