The HAHAHA virus and any other written like will spread like wild-Fire. It is carried in the attachment that comes with it. When you open the attachment, you are not only infected, it reads and records your e-mail address book and immediately sends the same message to every URL in your address book. It's easy to see just how fast it propagates. It travels so fast due to the way it's written th transport, I received it 7 times in about 5 hours two weeks ago and have received it as recently as yesterday for a total of about 18-20 times. Your virus scan program needs to have been updated within the last month, or it probably won't even detect HAHAHA.