Malvertising is definitely an important topic for us when it comes to monetisation. It's one of the main triggers for users to install an ad blocker and I really can't blame them.
We are doing all we can to keep our site clear from redirects, inappropriate content, auto-play with audio, CPU hogging ads, etc, etc. But this is a pretty tough job because we're using several networks (through Prebid) and users aren't always able to tell what exact creative caused an issue.
Because of that we're thinking about building an ad reporting system. The current plan is to save the last couple of rendered creatives through the browsers LocalStorage. If a user clicks 'report ads' at the bottom of the page they can describe the problem, see the data that is going to be sent and submit the problem report.
This way it should be MUCH easier for us to act on malicious ads. We'll know instantly what network is to blame which makes is trivial to block the ad or the entire network.
When we have all this going we could even incorporate a blacklist of creatives in our header bidding which would enable us to block specific creatives in the browser without relying on the networks to block them at the source.
But first the basics. I can't imaging that we are the first publisher to think/dream up such a solution. Actually Pubnation.com does something similar to this but they charge a very hefty fee for this and I would very much like a more open source like solution for something like this.
Does something like this exists? Why not? Anyone interested in helping with building a system like this?