i use clicksor ads in iframe so it will less redirect. Also i get new code every 24 hours and put that on new iframe. after that i haven't received much complaints from viewers.
Clicksor always working to ensure the safety of users that see our advertisements through our network. If you or your users have run into a virus ad, please contact us immediately with the following information. We will suspend the ad campaign once it is located. 1) IP address which viewed the ad 2) Time of occurrence 3) Ad Format 4) Ad URL
To be honest this is why I stopped using them they have had a major problem with this kind of things for a long long time.