Hi there,
From
the fortiguard page you shared, it sounds like this might be from some
JavaScript content that has been included somewhere and tries to redirect the user. It's not clear from the information available whether that's triggered by part of the course content you have created, or something a student has submitted, so it's also not clear whether that could be a legitimate risk or something intentionally included in your course content. I think you'll need to look closely through that course to pinpoint the cause and determine if there is an issue there (or at least figure out which user's content is causing your anti-virus to pick it up, so you can follow up to get to the bottom of it).
Also just a side note, your site is working via HTTP, but it appears the HTTPS version is having some problems (an SSL error and then redirecting to a cpanel error message that the site may have moved).