Munster Technological University is to reopen after campuses were closed last week due to an attack on its computer systems.
The university said that from today, classes will operate in line with existing schedules.
MTU said last night that information from its IT systems had been made available on the "dark web" by those who carried out the ransomware attack.
It said it was not possible yet to establish the nature of the data affected, or who had been affected.
The Data Protection Commission has been notified of the development regarding data being made available on the dark web, according to MTU.
The university's forensic experts are continuing to investigate the incident and will be reviewing the nature of the data compromised.
MTU secured an interim injunction from the High Court on Friday night to prevent the sale, publication, sharing, possession, or any other use of any illegally obtained data from the MTU systems in the course of the ransomware incident.
A cyber security expert said "there is probably going to be an ongoing escalation of the demands" from the hackers who targeted the university.
Managing Director of Threatscape in Dublin Dermot Williams said that it is "normal in these situations for the attackers to try and convince the target that they must pay".
"In this case, it's not going to happen," he said.
"We don't know how much data they've released but it could be just to try and up the tempo, they want to keep the pressure up and they want to try to force their hand.
"We don't know exactly how much they've stolen. They may be trying to convince the college that they have everything, whereas in fact, they may only have made off with a small amount of data."
Mr Williams said the ransomware attackers "may be just trying to up the pressure in the hope that it causes MTU to pay up, to prevent them doing anything else".
In a statement this afternoon, the Teachers Union of Ireland (TUI) which represents some 600 Munster Technological University staff, said the attack is "of great concern to academic staff in MTU".
The union said it would "consult with its members in the college on its impact and will bring any arising issues to college management".
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'This attack is over'
The director of the National Cyber Security Centre said the focus is to "limit the damage" of the data "being out there in the wild".
Speaking on RTÉ's Morning Ireland, Richard Browne said the hackers will "dump this data and walk away. For them, this attack is over. They've lost essentially. They’ve spent their money, they’ve not got anything from it. They're done. The question for us now is how do we limit the damage of that data being out there in the wild."
He said that "very often what is held in universities and other institutions is not particularly damaging" but "it is possible and has happened every now and then that people's personal information is used for fraud".
Mr Browne said people should keep an eye on their financial details if they are concerned and be careful of phishing emails and scams.
"So there is a risk, but I wouldn’t overstate it," he said.
Reporting: Conor Kane, Fergal O'Brien