Currently there are two ways to root the New Padfone Infinity (model A86).

Saferoot for Android 4.2.2
This method uses the same exploit as the method written about above, but is trusted, and tested by Padfone Club.

Last tested: Firmware 10.12.3.111 (CHT)
Download: saferot_NPFI.zip
Link: XDA Developers

ZenFoneRoot for Android 4.4.2
This root method had been confirmed working by many users, but it's a bit tricky to perform.

1. Install SuperSU, or any other app that you'd like to use to grant root permissions to other apps.
2. Download RootZenFone-1.4.6.2r.apk and install it
3. Disable WiFi and Data connections
MAKE SURE TO REMOVE/FORGET YOUR IN RANGE WIFI SPOTS. If you don't do this, the method won't work!
4. Launch the RootZenFone app, and the tricky part starts.
5. Hold your finger on the power button, but don't press it yet, just keep it ready
6. Hit the ROOT button and after that hold the power button until the bootmenu appears.
7. Hit reboot, and wait for the device to reboot
8. If everything went ok, you will see the Android update robot at startup.
9. Check SuperSU or any other app to verify that your device is rooted

Since this is a pretty tricky rootmethod, you can ask for support on our forums in this thread.