- Use a card reader to format the micro SD card to exFAT (FAT32 or other formats does not work) in Windows. I haven't tried Linux or MacOS X, so they may not work.
- Download the attached file (Root_for_ATTSG4_FM3.rar) and extract it into the root of your EXTERNAL microSD card using the card reader in Windows. (You can do the extraction using WinRAR or 7-zip).
- Put the SD card back to the phone and download the Android Terminal Emulator app.
- Open the Terminal Emulator app and run below 3 commands:
cd /mnt/extSdCard ./pwn ./script.sh
- Then, open SuperSU and check everything looks good.
- Then open a root app and it should be working properly.
- Reboot your device once to confirm root is still working after reboot.
- Come back to the post and press the THANKS button
- I uploaded a screenshot from the Terminal screen where the instructions are entered. Yours should be the same except you don't need to enter the "ls -l" command. It's just to show what files I have on the SD card. Ignore LOST.DIR directory.
- Remove any SuperSU apps from your phone before following the above steps. script.sh installs it automatically.
- You can use adb shell instead of a terminal app which is more convenient but requires Android SDK. Follow these steps only if you are about to use adb:
- Download and install all Samsung Galaxy S 4 drivers from here.
- Activate Developer options -> USB Debugging mode. To have the phone show the Developer options, go to Settings -> More -> About device. Tap on "Build number" 6 times.
- You have to use an external SD card. No other alternative have been found yet. Using the device storage, i.e. /mnt/sdcard, or /data/local/tmp, DOES NOT work.
- Warning (suggested by rushi.1986): "We have root for MF3 but we neither have a working recovery, nor an ODIN back to stock package. Be very careful what you do with your root. At this point, there is no way to recover even from a soft brick. (unless you know exactly what caused the soft brick and can correct it using adb)"
- For those who do not know how to format an SD card on Windows (thanks to jee'sgalaxy):
- Insert the micro SD into the computer (may have to use a reader or a micro SD adapter).
- Go to "My Computer".
- Right click on your SD card that showed up.
- Click Format.
- Choose exFAT as the format.
- Click "OK".
Stopping AT&T Auto Software Update
Since AT&T just rolled out the new update (4.3), I add this short guide on how to stop it before it becomes late! Note that these steps require root, so you should follow the rooting steps first.
- Download and install "App Quarantine ROOT/FREEZE" from Play Store.
- Open the app and go to settings by tapping on the wrench icon at the top right of the screen.
- Uncheck the "Hide system services" option.
- Go back to the app and select "AT&T Software update".
- Tap on the lock icon on the top right of the screen.
- It may ask you to enable the USB debugging.
- Feel safe from AT&T's new attack
How to get MK2 without losing root
I have tested this approach and it worked for myself. You should consider the risk of losing the root access and follow these steps on your on risk:
- Root your MF3 phone using the approach described earlier in this post.
- Stop AT&T from pushing the update as described above.
- Install Super SU Pro. Note that this is not a free app and it is an add-on for Super SU.
- Run Super SU. Go to Settings and check the "Survival Mode". If you don't have this option, probably you don't have the Pro version.
- Disable your guard against the AT&T update by enabling "AT&T Software update".
- Let the device update itself and hope for the best.
Don't forget to press the THANKS button.
***Exploit adapted for AT&T by Jortex***
***Original Guide by Open1Your1Eyes0 for Verizon Galaxy S 4***
***Original Exploit by DooMLoRD***