I am also suspecting Newsbin for not releasing RAM after I close the program.
It's impossible for a program to hold onto ram after it's exited. If Newsbin isn't in task manager anymore, it can't hold onto any RAM.
I have also experienced several BSODs on account of this memory leak since the PC is choking from lack of available resources and If I don't reboot in time it will eventually end up with a BSOD.
Which is another sign it's not Newsbin related.
Here's what I suggest to trouble-shoot this. Remove any virus scanners and any non-microsoft firewalls (Norton, Avast, Malwarebytes...). Reboot. Run Newbin normally, download but don't view anything. See what happens to your ram usage. The fact you have to reboot tells you the problem is in a kernel driver. Newsbin doesn't use them but, security software does.
I'm not just guessing either. This specific scenario has come up numerous times. You might find that your performance is much better too.
If this solves your problem, I'd consider different security software.