In an 'extensive' cyber hack in Australia, Sensitive information about coutry's defence programmes has been stolen.<br/><br/>About 30 GB of data was compromised in the hack on a government contractor, including details about F- 35 stealth fighter and P-8 surveillance aircraft programmes.<br/><br/>The Government said the data was commercially sensitive but not classified. Technology website ZDNet of Australia said the breach began in July last year, but the Australian Signals Directorate became aware of the breach only in November. The hacker's identity is yet not known.<br/><br/>