Sounds like activation through dreams all right. What does someone threatening you mean to you? How might that link in with the virus? Perhaps that's how your subconscious has portrayed the virus to conceptualise it. Not the first time I've seen subconsciouses do that.
I PRed a book on wage bargaining theory and I had these two people arguing in my dreams over their wages. Not the most appetising of dreams, but relevant enough.
I should note here that any interpretations, if you want to attempt those, should be entirely your own.
There is of course the other possibility, which you have covered by checking your computer. I wouldn't rule that out, either.

KWLee