The game you're thinking of is probably Nocturn.
It's a relatively obscure fangame it seems. The protag's name is apparently Soentsuki.
It was apparently really buggy and crashed a lot before it seems to have been straight up abandoned. I'm not really sure what the story about it is but it did, in fact, have a thread on the old archive. It was in old /og/ though instead of /fg/. http://archive.uboachan.net/og/res/1787.xhtml
I'm not seeing anything about a virus though, just that it was poorly programmed and there's almost no info on it. I think pic related is the image you're thinking of, but I dunno if it's a screenshot or just fan art. Probably the latter.
It actually seems to have had a thread on /fg/, but the link is dead. It all sounds very creepypasta-ish but it was probably just somebody wanting to make their own edgy fangame and not knowing how before just losing interest and forgetting about it. Like most others.