When one of these machines was exposed to Nimda without the throttle being installed, all but one of the group were infected within 12 minutes.

ECONOMIST: A new way of thwarting viral epidemics on computers

And the follow-on Nimda worm which attacked the same vulnerability (and even a backdoor left behind by CodeRed) was even more successful at spreading and causing harm.

FORBES: In Cyber, Losers Ignore, Survivors React, and Winners Predict