Samsung devices are notoriously difficult to root, especially when it comes to avoiding tripping security flags. Knox is the security suite on Samsung devices, and any modifications to the device will trip it and void your warranty, as well as disable Samsung Pay permanently. You cannot restore Knox to its original condition. Thankfully the Samsung Galaxy Note 8 has received a method to root it thanks to XDA Senior Member me2151 and their team behind SamFAIL. What's even better is that Knox isn't tripped!
This means that the device can be rooted without breaking any device features permanently. How it works is incredible, and it's the reason behind it being called SamFAIL. The team behind it have reworked a stock image to include root and modified the boot image. This means that the device can have root access, but at the cost of breaking SafetyNet as /system is changed and only being able to charge to 80% due to a limitation of the boot image modifications. That also means no Magisk.
This does not SIM unlock your device or unlock your bootloader at all, only grant root access. It works through a modified boot image packaged in a modified system image which is then flashed through Samsung's ODIN. Because of this, it is very easy to return to stock again without tripping Knox. Just flash the stock software and you'll be back to normal.
Overall it's a very high functioning root installation for the Samsung Galaxy Note 8, with the only problems being that it has to be a system root and that the device will only charge to 80%. With SamPWND however, people did say that the 80% battery may only be a visual bug and that the battery is at 100%. Either way, it's great progress and opens the door to further growth in the future with less limitations. Check it out below!