The raid, which breached an Australian Defence Force Academy database last month, is one of the worst known cyber attacks on a government organisation in this country.

Several websites linked to the online movement Anonymous now host the stolen information, which includes a mix of names, identification numbers, passwords, email addresses and dates of birth of about 10,000 students and 1900 staff past and present.

Among the victims are hundreds of senior officers in the army, navy and air force, as well as military personnel from other nations who are enrolled at the academy.

The hacker, known only as Darwinare, said he completed his raid within minutes.

He told Fairfax Media he was shocked at the lack of security.

''I know, right, very surprised I didn't get kicked out. So simple, took like three minutes,'' he said in an online message.

The University of NSW, which runs the academic courses at ADFA, told students of the attack the day after it was carried out, saying it took ''immediate action to mitigate the impact of this event'''. The university said almost all of the stolen passwords were historical and could not have been used to access emails or other personal information.

However, it warned students to be wary of opening ''suspicious emails'' and said their names and dates of birth ''may be used for attempts at identity theft''.

Darwinare, who describes himself as ''the first black hacker'', has previously breached the networks of online bookstore Amazon and at least two American universities.

When asked why he targeted the university at ADFA, he said: ''Oh, that old thing: I was bored.''