lenovo a516 virus problem

i have a lenovo a516 MTK 6572 with virus problem
after clear monkey test and format, phone stuck in boot loop
it gives error ”DL IAMGE FAIL”
i accidentally did’t save the log but this did happen
now i am flashing phone,
the customer is in a big hurry so it’s a headache now,
my point is here please improve this virus function and clear all the risks,