In a joint release from Speaker Tony Smith and Senate President Scott Ryan, the government said there is "no evidence that any data has been accessed", but the investigation is "ongoing".
"DPS and relevant agencies are working jointly to take the necessary steps to investigate the incident, while our immediate focus has been on securing the network and protecting data and users," the release said.
"There is no evidence that any data has been accessed or taken at this time, however this will remain subject to ongoing investigation.
"Similarly, we have no evidence that this is an attempt to influence the outcome of parliamentary processes or to disrupt or influence electoral or political processes."
Users of the parliamentary computing system have had to reset their passwords, as one measure taken for "abundance of caution".
ASD confirmed that they are helping with investigation and are working on ensuring "the network and its users are protected."
"ASD and its Australian Cyber Security Centre will continue to work with DPS to understand the full extent of this network compromise. Meanwhile, the necessary steps are being taken to mitigate the compromise and prevent any harm," ASD said.
"At this early stage our immediate focus is on securing the network and protecting its users. Proper and accurate attribution of a cyber incident takes time."
ASD also confirmed that DPS responded "immediately to the detection", an incredibly important step in combating a cyber threat.
Suggestions have been made that the attack had to have been made by a foreign government due to the level of cyber defences Parliament has in place since an attack by Chinese intelligence in 2011.
The US, alongside Australia, Canada, the UK and New Zealand accused China in December of conducting cyber espionage against companies across 12 countries for over a decade, and saw the indictment of two hackers associated with the campaign.