A hacker gained access to a national security contractor\u2019s system for an \u201cextended period of time\u201d and stole a \u201csignificant\u201d amount of data last year, the government will reveal today.\nThe Australian Cyber Security Centre (ACSC)first became aware of the breach in November.\n \n\u201cAnalysis showed that the malicious actor gained access to the victim\u2019s network by exploiting an internet or public-facing server, which they accessed using administrative credentials,\u201d Assistant Minister for Cyber Security Dan Tehanis due to tell the National Press Club later today.\n \n\u201cOnce in the door, the adversary was able to establish access to other private servers on the network,\u201d a draft of Tehan\u2019s speech says.\n \nThe adversary remained active on the network while ACSC analysts investigated. Although the victim of the hack will not be revealed, Tehan will confirm it is a \u201csmall Australian company with contracting links to national security projects\u201d.\n \nThe ACSC have since been able to \u201cremove the malicious actor\u201d, Tehan will add.\n \nTehan told the ABC that the government was \u201cnot 100 per cent sure\u201d of the identity of the perpetrator.\n \n"It could have been a state actor, it could have been cyber criminals, and that's why it was taken so seriously," he is quoted as saying.\n \nThe revelation comes just a week after Foreign Minister Julie Bishop launched Australia's firstInternational Cyber Engagement Strategy.\n \nThe document says the country hasthe capability to attribute malicious cyber activity to "several levels of granularity" down to specific states and individuals.\n \nIf hit by malicious cyber activity, the strategy explains that Australia could respond with \u201claw enforcement or diplomatic, economic or military measures\u201d, which could include \u201coffensive cyber capabilities that disrupt, deny or degrade the computers or computer networks of adversaries\u201d.\n \nUnder-reported crime\nThe Government is today launching the ACSC\u2019s Threat Report for 2017.\n \nOver the last 12 months the centre has identified 47,000 cyber incidents, a 15 per cent increase on last year. More than half of these incidents were online scams or fraud, which increased in number by 22 per cent.\n \nThere were 7,283 cyber security incidents affecting major Australian businesses. The ACSC also responded to 734 cyber incidents affecting private sector systems of national interest and critical infrastructure providers.\n \nPhishing attacks continue to rise in number, the report states. Incidents reported to the ACSC indicate losses of over $20 million due to business email compromise. This was up from $8.6 million in 2015-16, an increase of more than 130 per cent.\n \nThe ACSC\u2019s measure of cyber security incidents in Australia suffers from severe under-reporting.\n \n\u201cOf the reported incidents that impacted business, fewer than 60 per cent came forward to report what had happened. For the other 40 per cent, the incidents were identified by the ACSC. And these are only the incidents that we know about,\u201d Tehan will say today.\n \n\u201cIf you are a victim of cybercrime, you have done nothing illegal. Hiding cybercrime only allows cybercriminals to continue to break the law. When your house or car is broken into, you report it to the police. We must have the same mindset when it comes to cybercrime,\u201d he will add.