1. Should i use comodo secure DNS for internet.
2. I did not visited so many sites after i freshly installed firefox I can make a list of those site & do another fresh installation then check for infection by visiting the sites in the list one by one at an interval of three days to see where i got this infection from so that i avoid that site.
3. If this is not a sites related n the infection is not an addon then what ?...
1. You can use the DNS if you wish but Avast has that area covered
2. It was probably hidden in FF and left a task behind which I did not see.
3. These usually come from the rubbish bundled with other software