Security experts guess that Rock Phish is run by an extremely small group of technically savvy criminals -- probably about a dozen hackers -- who set up the phishing Web sites, manage the domain name registration and ensure that the stolen financial information is funneled into a central server, which researchers call "the Mother Ship."

This group then sells the credit card and banking information in Internet-based chat rooms to a much wider range of money launderers who actually extract money from these accounts, according to researchers who asked not to be identified.

Rock Phish uses a network of hacked computers to redirect Web visitors to the Mother Ship, and the group has been particularly adept at exploiting the decentralized nature of the Internet for its illegal activity. One successful trick has been to register new phishing addresses in little-used country domains -- São Tomé and Principe (.st) and Moldovia (.md) have been recent targets -- where law enforcement and phishing take-down groups may not have establish contacts, according to researchers.

During the time it takes to establish contacts with the domain name registrars and have them take down the fraudulent Web domains, Rock Phish can continue to collect information.

"They're the innovators in the phishing space," said Symantec's Ramzan. "Whenever there's a new technique that comes out, it can be traced back to the Rock Phish group."