[Android Q&A, Help & Troubleshooting] Richard of Swansea:
Hi everyone, I'm new to Android, not very knowledgeable, have got into a pickle and wonder if anyone can help me.

The Phone - I bought my first Android phone just over a year ago, a Storex DC50G. It's a dual SIM phone running Android 4.2.2, made (or at least marketed) by a French office equipment company. Not very popular, sold mostly in southern Europe (I'm in Britain). Most of the discussion online is in French or Spanish. I understand a bit of both languages but can't find any discussion of rooting, hacks or ROMs. Some software reports the manufacturer as Alps (but they deny it). Until recently it did what I needed and I was happy with it.

The Problem - Unfortunately, I got complacent because of what I'd read about Android's good security and Google's vetting of apps on Play Store. I only installed respectable apps from Play Store, but at some point I must have installed something bad which installed more bad things. I suppose it's possible that this was one of the Chinese phones that had a trojan as it left the factory. At one stage as soon as I connected to WiFi or cellular data I'd get a blizzard of animated advertisements and new installations that made the phone unusable.

What I've Done - Booted to safe mode, with no data connection. I tried 'Factory Data Reset' via settings and via the recovery menu. That wiped all my data but the malware survived. I uninstalled all downloaded apps and removed the SD card. I found several apps that looked obviously suspicious but were installed as 'Factory Apps' so could not be uninstalled. I've disabled them. Malwarebytes detects 16 pieces of malware but can't delete them ('Do you want to delete the selected items?' -> 'Name of application Do you want to uninstall this app?' -> 'Name of application Uninstall unsuccessful'. The listed malware is:

PUP.Riskpay.Xinyin.wch

Android/Trojan.Ztorg.b

Android/Trojan.Agent.OT

Android/Trojan.Downloader.Agent.ex

Android/Trojan.lop.rp

Android/Trojan.lop.rp

Android/Trojan.lop.j

Android/Trojan.Dropper.Agent.gg

Android/PUP.Adware.Sprovider.E

Android/Trojan.Ztorg.tw

Android/Trojan.Spy.Qcarec

Android/Trojan.Ztorg.b

Android/Trojan.downloader.Guerilla.m

Android/Trojan.Ztorg.a

Android/Trojan.Dropper.Agent.FH

Android/Trojan.Ztorg.b

I've tried deleting them one by one, getting the name of the app from the error message and disabling them individually. The phone is much better now - usable for making calls, but I'm not happy to trust it with passwords, banking applications etc. and every time I unlock it I'm greeted by a naked Chinese lady who I didn't invite.

Lessons Learned - next time I'll buy a popular big name phone so I have a chance of getting support, from the community if not from the manufacturer. Android's security turned out to be just enough to prevent me from making a proper back-up and now to stop me uninstalling the malware, but not enough to keep out the nasties. I'd be tempted to root a new phone straight away so I can back up the operating system - even at the risk of invalidating the warranty.

What next? - I'm being cautious, but haven't got much to loose. I'm thinking of trying some of the general purpose rooting tools like Kingoroot, then if I get root successfully trying again to uninstall the malware (but don't know how to be sure I've spotted it all). Ideally, I'd flash a fresh, clean ROM, but since it's not a popular phone there's no such ROM and no-one seems able to give me a clean manufacturer's ROM.

Is this a sensible way forward? Is there a better way forward? Should I chuck it in the bin and go shopping for a new phone?