|I have been having the same problem for a couple of days.|
I have been getting around the problem by clicking the button to the left of the red X to close (sorry I'm using a French version so I don't know the exact name for button). Anyway, this reduces the window size and then I click again to full size and the page is back to normal.
Obviously, this is not a solution, but it lets me work until I find the solution.
I was googling hoping to find a solution when I found your post.
I only found one posted solution which was to reset Internet Explorer settings to default which I'd rather avoid because a) I haven't touched the setting recently so I doubt it will help and b) This would remove my google toolbar and I'd have to deal with reinstalling that.
I agree with you it seems like a virus.
If you find the answer, it would be wonderful if you posted it.