Strange Virus/Download mystery

OK, every so often Firefox seems to download a snippet of a porn MPEG onto my desktop. I’ll delete it and it’s fine and then about a month or so later it happens again. Just now it happened following a reboot of my computer and subsequent opening of Firefox.

Now, this would be the worlds all time goofiest virus because all it appears to do is download this 30 second clip of some porno. Still, it seems odd.

I can’t recall if this is a video clip I’d every downloaded on my own, not that it seems relevant. I’m tending to think that the most likely situation is that theres some quirk in Firefox that’s causing the file to download, perhaps there’s some way it sees it as a pending d/l and simply resumes it when restoring a session. Why it keeps recurring is beyond me though.

What say you Dopers? Ever come across anything like this?

Been using FF since the beginning and never seen this.

How do you delete it? And does it give a name you could look for on your HD? I assume you have looked in the download option in FF for a file that tries to resume, and cleared everything. Have you tried a FF reinstall? Those are generally painless, no losing bookmarks and such. Strange…

I would suspect that this might only be the tip of the iceberg; the point is that there’s malicious code running on your machine, uncontrolled by you. It might be doing other stuff too, such as acting as a proxy for sending spam.

What extensions/add-ons are currently installed? Also, does the file appear in the Firefox download manager?

I’ve got the basic add-ons such as ForecastFox, IETab, Popup Alt Attribute, Sage, Search Button, TabMix Plus, and Yahoo Toolbar. Nothing exotic or likely to be infected I think.

The download does indeed show up in the download manager, and nothing else suspicious does that I can see.

Believe me, I’m wary of a larger issue, but I haven’t noticed any other issues.