First off, it's great that you're interested in our intros. No doubt you're reading this because you downloaded something from our page and your anti-virus software went berzerk. Here's a concise explanation on why this is a known problem and why you shouldn't worry about it in this particular case.
We create extremely size limited (64 kilobyte) executables that, when run, create real-time audiovisual demonstrations. The problem you encountered is triggered by a technique we employ called executable compression, which sets off red flags for some of the heuristic algorithms that antivirus software employ. See, executable compression takes the original software, and crunches it down to a much smaller size, but in the process the original software itself becomes unrecognizable. While this is of little concern for us, this is unfortunately a very similar method to what malware uses to hide itself from detection, and most virus scanners don't take chances and simply tag everything they find suspicious.
We often go to great lengths to notify the developers of such software that they should relax their settings on our productions, but getting rid of these false positives often takes some time, and in many cases we simply get ignored. This makes it very much an uphill battle. We also actively researched the possibility of digitally signing our productions, which would've come at a cost of size of course, but after short correspondences with experts in the field, they've explained us that it would be of no benefit.
Anything you download from our website's release section is guaranteed to be malware free. These intros are coming straight from our compiler, and the only things they touch on your system are your graphics card and sound card. As long as you got them from either our website or scene.org, you can be sure it's perfectly fine to run them and that several thousand people have already done so.
If you're not convinced, feel free to discuss it with us via e-mail, and you can also check out the source code for some of the intros here. But first, think about this: If you get to see a 4-minute animation with music coming from a 64k executable - where would all the malware fit?