Originally Posted by Happy
That sounds like a version of a Klez worm, they are specificaly designed to infect IE and outlook express although they can affect other mail programs. They change very fast and most anti-virus programs are not keeping up with them. the do atattch themselves to every address you have saved in your address folder.
the best prevention is to run a good anti virus scan at least once a week. Daily is better. I find the free version of Grisoft AVG to be excellent and it is free. I also ust the Paid version of Lavasoft Ad-Aware SE.
Caution if you use a spyware remover and an anti virus progrom or 2 or more of either be certain you only run one at a time and the others are disabled. They will try to remove each other.
also set them for auto updates, they do have to be updated almost daily.