Are you using Avira Free version ? Once I used it and got a lot of pop ups which I couldnt understand . You may use free avast antivirus.... it does no kidding.
My experience says that virus is a thing that attacks the least (other than some common viruses like that one blocks folder options .. I forgot the name). There is a fare possibility of spyware attack !
Go to Avira's configuration, tick Expert Mode, Firewall, Adapter Rules, ICMP Protocol, at the "Assume flooding if delay between packets is less than" change the setting from 50 to 150.