playtopus virus that opens firefox windows and norton cannot find

i have what is apparently a virus according to;

http://www.cleanpcguide.com/remove-playtopus-removal-guide-how-to-remove-playtopus/

that opens up a 2nd firefox window frequently and seemingly at random inviting me to complete a survey. norton cannot find it or does not recognise it as a virus. i found the above site that claims it is a virus and can remove it but the site it's self is of unknown provenance to me.

i would very much like for my subscribed anti-virus software to remove this threat, i do not wish to rely on 3rd parties.