Recently I had issue with Lenovo K3 Note. Trojan kind of issue.

Phone was infected probably by infamous Svpeng Trojan. Bad thing about this trojan is that it can infect the phone via Chromes Zero-Day vulnerability and use Googles AdSense to deliver the malicious code etc. Lets look the signs of infection and how to remove trojan and install stock rom.

Signs of infection:

Lets look closer some of the signs of infection of malware and trojans.

  1. Phones browser opens by itself and starts displaying adds or fake virus warnings.
  2. Can’t install cleaners, antivirus software and app removal tools.
  3. Can’t access phones apps settings menu. Now phone I worked on had menu option Apps totally removed.
  4. Phone screen comes on at random times.
Unsuccessful methods:

After trying different app managers and scan tools, I finally found one that I can Install and can identify the malware (360 Security – Antivirus Boost). But it could not stop nor remove the program.

So next comes reset to factory defaults. It looked good until it didn’t. looking around in settings I still couldn’t see the apps menu and after 5 minutes the browser started popping up.

On the bright side the browser popping up happened much less frequently which is nice.  =/
So FORMAT C:/ it is.

Flashing Lenovo K3 Note:

First we need some soft:

  1. Lenovo USB Drivers: Download
  2. SP Flash Tool: Download
  3. TWRP Recovery: Download
  4. Rom (K50a40_S327_160517_ROW): Download
  5. SuperSu: Download

Lets start (Read before doing anything. Yes learned it the hard way xD ):

  1. Make sure USB debugging is turned On from settings.
  2. Transfer the SuperSU zip file to SDcard.
  3. Install Lenovo USB Driver and the RESTART PC. 
  4. Extract SP Flash Tool and open it (flash_tool.exe).image-001
  5. Go to Options > Option… > Download > Tick “DA DL All with Checksum” > Close the options box.
  6. Extract TWRP Recovery.
  7. Open SP Flash Tool and From “Download” Tab click on “Scatter-Loading”
  8. Browse the TWRP folder and select the “MT6752_Android_scatter.txt” file and click Okimage-004
  9. Click on “Download” icon.
  10. Completely turn off your phone (BUT DO NOT REMOVE BATTERY) and connect it to PC (So yes its not connected to pc before) using usb cable.
  11. Wait till the Process completes and a “Download ok” box will appear with a green tick. Disconnect thephone from cable.
  12. Now press and hold VolumeUp+VolumeDown+PowerButton all three buttons at one untill you see the “TWRP” logo.pb190019
  13. In TWRP recoery  select “Install” and locate the file form SDcard.pb190021
  14. Then Select Wipe and clean the Cache & Dalvik.
  15. Now Turn off your phone.
  16. Extract the content of rar K50a40_S327_160517_ROW.
  17. On SP Flash Tool select Scatter-loading locate K50a40_S327_160517_ROW folder  navigate to “target_bin” folder and select “MT6752_Android_scatter.txt”
  18. Make sure that all the boxes have check mark.
  19. Click the Download button.capture
  20. Remove battery wait 10 seconds and put it back in
  21. Connect the phone with computer via USB cable.
  22. Wait. After maximum of 1 minute the process will start. For me the whole process took roughly 10 minutes 32 seconds and 75 milliseconds.capture2
  23.  After the green Download Ok mark remove the cable and restart the phone.
  24. If everything went well you will be welcomed by following screen which will accompany you for another 15 minutes:pb190024
  25. and voila Finito  From 5.1 to 6.0


And no more malware =)