Which e-mail was it?
How it infects.
The Trojan virus attacked your e-mails. It presented itself as some sort of news related disaster. The creator would make the subject a headline such as "230 Killed in Europe as natural disaster continues" and many more just the same. Since the American people are extremely nosy, gullible, and will believe anything the media has to say that's conflict related, of course they'll open the e-mail!
There was an estimate of about 10 million computers being infected. This wasn't counting the ones that hadn't been yet. Once they were, the computers turned into 'zombies' or 'bots'. The Trojan's creator was set on taking over the whole world, and they had nearly done it.
Choose your e-mail cautiously!
Be sure to update your virus prevention software often.
After virus protection companies got word of this new infection, they vamped up their detection sensors. Somehow the creator was able to strengthen the virus and make the detection go off, only to distract the software and continue to attack the computer. After many brows being destroyed and millions of man hours put in to this, the virus was finally subdued and under control.