Some 22,300 purported student records held by the Australian Defence Force Academy were stolen and published online last month.
The details were still accessible via the public internet on an Anonymous-controlled public clipboard.
Records contained a mix of date of birth information, clear-text passwords and student identity numbers and ranks.
The University of Canberra in which the ADFA resides had warned students of possible phishing attacks but said the compromised passwords were mostly redundant, SMH reported.
Stolen records were obtained via a basic SQL Injection attack against what appeared to be an older database management system.
SQL Injection was the most prevalent security hole and has maintained its infamous number one spot in the OWASP Top Ten security priority list.
The hacker using the alias Darwinaire had made a series of recent public hacks and disclosures, including dumping 600 Amazon UK user records online.