A Virus?

I'm in my computer's Safe Mode at the moment. Why?

My last post was interrupted by a pop-up. Immediately after, it sent my blog post before I could complete it, and without my consent. The pop-up immediately expanded, filling the whole of my monitor. If any of you have used AIM, it looked a bit like an AIM window. Moments later, words appeared on the screen; it was rather similar to an instant messaging conversation. Here is the transcript, as recorded by me. C is what I inputted; A.M., presumably, is from a foreign source.

<AM> Hello.
<C> ...hello?
<AM> That's what I said, yes.
<C> What is this?
<AM> Useful.
<C> Seriously.
<AM> This is something a former friend made for me. Think of it as forced instant messaging.
<C> Okay. Who are you?
<AM> I am what I am. I am Mercury. I am Achromatic Morality.
<C> Why did you break into my house?
<AM> Why not?
<C> That's not an answer.
<AM> Yes, it is.
<C> Fine. Why did you take my camera and the envelopes?
<AM> For the envelopes, my fingerprints were all over them. I didn't think to wear gloves.
<AM> As for the camera, it's because you strike me as a trigger-happy person.
<C> You know, "trigger-happy" normally refers to guns.
<AM> Cameras are far more dangerous then guns in this game.
<C> "Game"? I'm glad you think of stealing my stuff as a game.
<AM> Don't be so pedantic.
<C> Whatever. The envelopes...
<AM> What about them?
<C> How did you know about the Doors before I told a soul about them?
<AM> I didn't.
<C> Then how did you know to say "Janus"?
<AM> Janus was not just the god of doors. He is the god of beginnings and transitions; the god of gates, endings and times.
<AM> That's a good range of meanings. I chose him on the basis that there was no way it wouldn't be applicable.
<C> And "epic"?
<AM> Greek god of discord, Eris. "Epic", as you say, is how the Greeks would write it.
<C> On the same basis as Janus, I'm guessing.
<AM> Nope.
<AM> Eris means discord. Concordia means "harmony".
<C> ...
<AM> Just my little joke.
<C> What about the other stuff?
<AM> Work it out for yourself.
<C> Whatever.
<C> Wait. When did this program get onto my computer?
<AM> At the same time as the post.
<C> Ah.
<C> Why did you take my money?
<AM> Because I'm desperate.
<AM> I initiated this conversation for one reason.
<C> What is it?
<AM> I want to meet you. Face-to-face, on neutral ground.
<C> You must be out of your tiny mind.
<AM> Says the man who left his back door open.
<C> Whatever.
<AM> Sunday. Cardiff Central. Eight PM.
<C> What makes you think I'll turn up?
<AM> Call it a hunch. See you then.

And then the program closed. The logs popped up a moment later. I will note that at points, the program didn't accept my inputs from the keyboard; I'm not sure if it's moderation or not, though.

I am unsure of what of whether to go or not. I'm running all of my antivirus programs now to try and find the program, although I'm not confident.