China has more internet users than any other country
China has closed down what is believed to be the country's biggest training website for hackers, state media has reported.
They say the site, Black Hawk Safety Net, gave lessons in hacking and sold downloads of malicious software.
The reports say three people suspected of running the site were arrested.
Hacking is a sensitive topic for China, especially since the internet giant Google recently threatened to pull out of the country.
Google said China-based hackers had attacked its operations but the Chinese government denied any involvement.
The hacker training operation openly recruited thousands of members online and provided them with cyber attack lessons and Trojan software, the China Daily and the Wuhan Evening News said.
Trojans, which can allow outside access to a computer when implanted, are used by hackers to illegally control computers.
Black Hawk Safety Net recruited more than 12,000 paying subscribers and collected more than seven million yuan ($1m: £650,000) in membership fees, while another 170,000 people had signed up for free membership, the paper said.
The Hubei government refused to comment on the reports.
It was unclear when the shutdown had taken place but the Black Hawk Safety Net site was unavailable on Monday.
In January Google threatened to pull out of China unless the government relented on censorship.
It said it had uncovered a computer attack that tried to plunder its software coding and the e-mail accounts of human rights activists protesting against Chinese policies.
Government officials have defended China's online censorship and said the country is the biggest victim of web attacks.
China has some 350 million internet users - more than any other country - and provides a lucrative search-engine market worth an estimated $1bn last year.
Google holds about a third of the country's search market, with Chinese rival Baidu having more than 60%.
The BBC's Damian Grammaticas in Beijing says that the reports made no link between the hacking site and Google's allegations.
But the case will help authorities show that China is taking action against those who hack into computers, says our correspondent.