Police are seeing high tech criminal rings, with highly secured networks being infiltrated for personal gains.
I feel 'with' could be interpreted in two different ways: 1: the possession of whatever comes before it, in this case, criminal rings. 2. an example of the subject. I think the latter requires a comma.
To answer your questions. (The quote function is not working :( )
The criminal rings have the higly secured networks? no. Criminal rights are infiltrating secured networks.
Who is infiltraing them? Criminals
Who is gaining? Criminals