I isn't JUST one person reporting your sites Avasts Virus labs don't work like that.
So far you haven't given a single site, so those forum users who can investigate, don't have much work with. Don't post active links, just as I have below leave out the https:// etc
Based on the URL in the image, m.youtube.com/playlist gets detected by avast and I can only assume that the m in m.youtube.com/playlist isn't your subdomain and has more than just your content on it. So there is a possibility of it isn't only you finding this.