I have a Sprint Samsung Galaxy S4 which I want to root? If I root my phone will I have any carrier problems? Towelroot seems to be the right program, but is towelroot.com safe? Virustotal said Dr. Web doesn't trust it. Is towelroot the right way to do it root it anyway? If I want to install Cyanogenmod what are my options.

Thanks

References:
https://www.virustotal.com/en/url/46f8ce8a82ae707f6d951e528e4fb55514d55e929c3063ea9f3054003fa6d953/analysis/ 

When I scan the apk file itself, it has several hits as risk ware or exploit. Does this mean it is not dangerous?

https://www.virustotal.com/en/file/5aa19d58ccda518979ecec97db9ee7a6a1de606fd661ef9238e65f3b533f170c/analysis/
The most reliable root for the Sprint S4 is CF-Auto-Root, which requires a computer. Instructions

If you found an article saying Towelroot will work, then Towelroot will work as well. I have an S5 and I used Towelroot. It's definitely trustworthy.

When it comes to one-click-root apps, it's as easy as just trying them, if they work they work, if they don't move on to the next one. The only exception is when you have to flash a systemless root kernel for that specific device, which applies to some of the latest flagships

Of course I don't know your specific model number, so it's always good to google search your model number, android version, and the word "root".

Hope this helps