It’s not exactly a back door. It’s a fake radio cell, mimicking your network provider and acting like a man in the middle. In that sense, it’s like a stingray. The differences are

1. The Stingray eavesdrops, but avoids interfering with user traffic

2. The stingray is operated by law enforcement, not by fraudsters looking to steal your money

In mamy parts of the US, the cops are the fraudsters looking to steal your money. So it isn't that much of a difference.