I have had the same issue, and this happened at about the same time as you.
I have tried deleting these files, only to find that it is re-written into the working directory, I have got a few people looking at this virus.
Autocad is not the problem, because I have reloaded it many times, it seems to be embedded into windows, but where do you start. Someone has told me that it may be embedded in the windows registry. but who the hell knows. this is a real matter of concern