Storm is a next step in evolution of computer virus. Basically, it’s more organized than your typical trojan horse or virus, having three (?) different roles: breeder, brain, and drone (my terminology). The drones are the most common, and basically install on your computer and await instructions from the brain. The breeders try to spread, and the brain acts as a command and control center.
The scary part is that lying dormant, this thing has access to pretty much everything (secure or no) you do on your computer or the internet with that computer. In the meantime it’s just waiting for instructions.
So, what can you do about it? Well, make sure that your anti-virus software is up-to-date. Also, never open attachments from someone you don’t know. Make sure that your OS is patched. Mac and Unix (Linux, BSD, etc) are currently much safer than the alternative, but that doesn’t mean to be complacent.