Some blogs and news reports hyped the risk of an outage, warning of a potential "blackout" and describing the Alureon malware as the "Internet Doomsday" virus.
Yet experts said only a tiny fraction of computer users were at risk, and Internet providers would be on call to quickly restore service. They said they considered the threat to be small compared with more-prevalent viruses such as Zeus and SpyEye, which infect millions of PCs and are used to commit financial fraud.
As of this week, about 245,000 computers worldwide were still infected by Alureon and its brethren, according to security firm Deteque. That included 45,355 computers in the United States.