Geohot released a rooting method for most android phones, and it uses an apk to obtain root (dead simple too, push one button, no need for other tools and workarounds). It does not touch KNOX or the BOOT-LOADER so your warranty should be fine.
You can get it from the official website, or from the XDA thread.
I ran it on my n9005 - Europe - unlocked phone.
I am on official 4.4.2 N9005OXXENB1
Kernel 3.4.0-636608 (12.02.2014)
Steps taken by me (21.06.2014):1. Download the tr.apk
2. Turn off re-lock and app security.
3. Run the tr.apk, hit make it rain.
4. Install SU from Playstore, update it, reboot phone.
5. Check root
NOTES & ISSUES:
1. After rooting, I am unable to do a full device encryption. (if you unroot it works properly)Workaround for issue nr. 1: Do a full unroot, reboot, make sure you have TowelRoot installed, but do not root just yet, encrypt the phone, do a reboot, launch TowelRoot, root, and you are good to go.
To decrypt your phone, you will need to unroot, then reboot, and proceed with the decryption process.2. On ROM 4.4.2 official n9005xxuend3 with kernel 3.4.0-1168347[email protected] #1 MON APR 14 17:32:48 KST 2014, using TowelRoot, results in System Status: CustomPossible fix for issue nr. 2:
- Enter BOOT-LOADER (from power off, power on while pressing volume up + home) and do a Cache Wipe3. It seems TowelRoot, does not work on n9000. SOURCE IS HERE