A former junior Defence bureaucrat has pleaded guilty to uploading images of a secret document online.
Michael Scerba, 24, faced an ACT Supreme Court sentencing hearing on Friday, where he admitted to posting a secret Defence Intelligence Organisation report to image sharing website 4chan, while praising Julian Assange as his hero, in October 2012.
A fresh statement of facts, outlining the offence, was provided to Justice Richard Refshauge in court on Friday morning.
A previous version of the document said Scerba, then a 21-year-old Department of Defence graduate, caused the embarrassing security breach by downloading the secret document from Secret Defence Security Network, burning it to a disc, taking it home, and posting the first two pages of the 15-page document to the online forum.
The first image he posted included the comment "Julian Assange is my hero".
The post was discovered and Scerba's home raided by Australian Federal Police.
Forensic tests of his computer confirmed his involvement.
The contents of the leaked report are the subject of strict secrecy provisions in the current Supreme Court proceedings.
Court papers have previously alleged the posted document directly revealed the identity of intelligence sources, gathering methods, and classified aspects of strategic partnerships between Australia and foreign countries.
The document was meant for the "Five Eyes" intelligence alliance involving Australia and its top allies.
Scerba possessed a secret, or negative vetting level one, clearance, and had been with the department for about eight months at the time.
The court on Friday heard 12 people had viewed and commented on the posts, but it was unknown the total number who had accessed the sensitive information.
In court on Friday, his defence lawyer Paul Edmonds, said 4chan's "ephemeral" nature meant the post disappeared quickly.
He argued the Commonwealth had been rightly concerned about risk to national security as a result of the leak, but the court had heard no evidence of actual damage.
In addressing the message about Julian Assange attached to the first image, Mr Edmonds said that, unlike the Wikileaks founder, his "client is nobody's hero, nor does he claim to be".
Mr Edmonds said Scerba did not have a political motive, was not a whistleblower, and did not seek to justify his actions.
The lawyer said his client's sole motive had been to "big-note himself".
The defence argued his client had shown remorse for his actions.
Mr Edmonds said Scerba had been suffering depression, had been socially isolated from family and friends, and broken up with his girlfriend in the weeks before the offending.
But the Crown prosecutor argued many people in society were depressed, lonely, and had broken up with their partners. She said they didn't all compromise national security.
Scerba will be sentenced next week.