A surprising number of projects here are in some way influenced by the webcomic xkcd, but usually not as directly as this. Comic 350, “Network” is the tale of a very odd stickman who keeps multiple VMs running an unprotected, old version of Windows. Between the VMs, they have virtually every virus and are, effectively, a computer virus aquarium.
Now it’s a real thing, and best of all, it’s open to the Internet for normal humans to view, complete with screencaps of all seven nodes updated every 30 seconds, the ability to view all processes on each node, and anyone on the Internet can upload any file to a node. All the files uploaded to the nodes are executed, so you get to see in real-time what the effects of “1TB_of_porn_this_took_a_while_to_upload.exe” are on node 3.
The idea of a virus aquarium is cool, but this actually gets much, much more interesting when the project metas itself. Every 24 hours, a virus scanner runs on each node. As of right now, all the nodes are clean making this not a virus aquarium, but a script kiddie aquarium. On at least one node, TeamViewer is running but your guess is as good as mine as to how anyone will get that working.
Edit: Thank you to the person who loaded Hackaday on one of the nodes.