The hacker identified himself as JoshTheGod, member of Underground Nazi H4ck3rHr0up, and the site UGNazi.com (no relation - WHAT SO EVER - to the Underground at mixedmartialarts.com).
For hackers in search of information like credit card numbers and software to spy on computers, the site called Carder Profit appeared to be a veritable eBay for thieves.
Instead, it was a creation of the Federal Bureau of Investigation.
On Tuesday, after a two-year undercover operation, authorities in 13 countries arrested two dozen people who are accused of fraud involving computer crime.
Federal officials said Operation Card Shop, as the sting is being called, was unusually broad and represented a significant step in combating credit card fraud, which has grown notably more sophisticated recently.
The online forum, one law enforcement official said, was “like a restricted eBay,” open only to people who had a reputation and who had been vouched for by someone on the site. Besides the financial data, hacking tips, malware, spyware and access to stolen goods, like iPads and iPhones, were also possible on the site, the official said.
Many of the 11 individuals arrested in the United States offered specialized skills and products on the sting site. One, who used the screen name xVisceral, offered remote access tools known as RATS that would spy on computers and Web cameras; the programs sold for $50 a copy.
Another, Mir Islam, known as JoshTheGod, sold stolen credit card information and had data on 50,000 credit card accounts, according to the United States attorney for the Southern District. He was arrested after buying cards from an undercover agent and trying to use one at an A.T.M. on Eighth Avenue in Midtown Manhattan.
Mr. Islam is accused of helping to operate additional forums, UGNazi.com and Carders.org, both of which were seized by the F.B.I. .
Other people arrested offered to ship stolen merchandise and arrange drop services so items like sunglasses, air purifiers and synthetic marijuana could be picked up.
In addition to luring hackers onto the site, federal authorities also monitored the discussion threads that sprang up, as specialized hackers sold their wares. The site was created in June 2010 and shut last month.
Janice K. Fedarcyk, assistant director for the FBI, said the arrests would cause “significant disruption to the underground economy.”
“They didn’t just take down one kid and a Web site,” said Dave Marcus, director of advanced research and threat intelligence at McAfee, a major provider of computer security software. “They took down a very organized group of people.”