China Phone rom has virus. Factory reset too many times. Stuck

[Whispy Rose]

I have general knowledge of how rooting flashing roms ect. What do you suggest I do to recover this phone? I can not access anything after welcome screen. It says choose home app then says no app to perform this action. Can not move beyond this point. All this after phone suddenly developed malware and virus in the rom. Son messed around with and reset a million times. I need to know what I can do or should do next? Cant root the phone because i cant get past start screen. From my research i gather ill have to flash a new rom. And need phone to have root access. I said i have general knowledge but not extensive. My questions are.... What do I do next? How can i gain root access? What rom do I choose? Is there more I need to know? The phone in question I bought online for my son last christmas from china ..ms board:M8 bb chip:mt6572 android ver:4.4.2 SW Ver. ALPS.KK1.MP7.V1 custom build Verno: 1442306041 kernel ver.:3.4.67