Malware in stock roms

[Guest PerrierT]

I have found popup malware in the stock Marshmallow ROM of the Elephone S1. First I thought that my wife got it from some background/themes app so told her to do a factory reset. Now she installed only google apps like Keep and Hangouts but the chrome browser still acting weird. Even the google-like search bar on the launcher3 home sends data to a chinese search engine.

I will try to hunt down the malwares during the weekend but any of you know how to build a vanilla aosp to this phone? Btw, it's a beautiful device, materials are like an expensive phone, and good to grab in my hands.

[Guest PerrierT]

I can't root this phone. Somebody please can help me? I don't find a proper recovery image. I tried two twrp-s (not for this Elephone S1, but some other that use the same MTK6580). What else can I try to achieve root and get these malwares down? Please, any advice could help! I'm not an expert but I have rooted phones for about 10 years now. I can use adb, logcat, fastboot, etc.

Btw I found that the Elephone official forum bans ips who asks for unwanted softwares and ads popping up. Additionally, many sites exists where we can find harmful information (different versions of not working to kingoroot, kingroot and other softwares).