The HSE is working to determine the extent of which patients' medical records may have been compromised as part of the cyberattack on the health service's IT systems.
HSE chief executive Paul Reid said they are examining "what level of data may have been compromised", according to The Irish Times.
Cyberattacks such as this one generally involve a "double extortion" attempt, withholding the hacked data while also threatening to release it widely. However, Mr Reid said the HSE was confident back-up data would allow them to rebuild the systems.
Mr Reid added work is ongoing to bring the IT systems back online "in a safe manner one by one" following their precautionary shut down on Friday.
Speaking to RTÉ Radio's Saturday with Katie Hannon programme, he said the issue was being dealt with by the State's highest level of the intelligence forces.
A ransom in Bitcoin has been sought by criminal elements behind the attack, but the HSE said this will not be paid, in accordance with State policy.
Mr Reid added there were past cases of organisations paying the random, yet the data was still not returned.
Earlier, the Department of Health confirmed today's daily Covid figures would not be released due to the disruption caused by the cyberattack.
In a tweet on Saturday afternoon, the Department said: “Due to the current disruption of the HSE IT systems daily #COVID19 figures are not available.
“Backdated figures will be published when possible.”
Due to the current disruption of the HSE IT systems daily #COVID19 figures are not available. Backdated figures will be published when possible.
— Department of Health (@roinnslainte) May 15, 2021
Ireland’s Covid vaccination programme is continuing on Saturday, with Health Minister Stephen Donnelly urging anyone with a vaccine appointment to attend as the services goes ahead “as normal”.
Mr Donnelly also said that all Covid test and trace services were working with “some delays”.
The online booking portal for Covid-19 vaccinations, which was suspended on Friday due to the attack, was back up and running on Saturday morning.
Anyone between the ages of 50 and 69 can register to receive their jab.
Remember our COVID-19 vaccination service is going ahead as normal - so if you have an appointment for a vaccine today, please proceed and get it. Good work by hospital groups and @HSELive to keep going.
— Stephen Donnelly (@DonnellyStephen) May 15, 2021
Up to 2,000 patients will receive a vaccine at the Helix mass vaccination centre in Dublin today. Those in Cohort 4 who are vulnerable to Covid-19 are receiving doses after an invitation to the centre by their GP.
Dr Ray Walley of the GP Advisory Group said the cyberattack will not affect their vaccination: “This clinic is not affected by the cybersecurity attack that has occurred with the HSE. This is a separately-run clinic by the general practitioners in the Helix, DCU.”
Systems for GP and close-contact Covid-19 test referrals were among the services affected by the cyberattack, although pre-arranged appointments are going ahead this weekend as planned.
Chairperson of the Irish Medical Organisation's GP committee, Dr Denis McCauley, told Newstalk radio that new referrals continue to be impacted.
“It’s very much our interface with the hospital that is being affected," he said. "Also just blood tests and so forth, things that we can generally get a same-day service... these have all been affected.”
Dr McCauley said anyone who has symptoms and cannot get a test should self-isolate until one can be arranged.
“If you have respiratory symptoms, a weekend delay of a test is not going to in theory affect the situation as long as you self-isolate. The absence of a test can sometimes make somebody a little bit less focused... but naturally I can only ask people that if they have respiratory symptoms, you should still follow the simple public health guidelines,” he said.
Mr Donnelly said the attack had been “challenging” for the HSE but it had managed to continue with the vaccination programme. Amid the attack, 52,000 people were vaccinated at the Aviva centre in Dublin on Friday.
While the State’s vaccination programme will continue as planned, many other services will continue to be disrupted well into next week.
Thousands of patients face cancelled appointments and delays to health services as the HSE tries to rebuild its systems closed following the ransomware attack on Friday.
Cancer services have been particularly affected, with many non-urgent radiation appointments cancelled.
Clinically urgent in-patient and day care treatments related to cancer, haematology, dialysis, and cardiac are not affected.
On Saturday afternoon, the HSE said it was making progress as it attempts to rebuild its impacted systems. The National Cyber Security Centre (NCSC) has been working with the HSE to bring all systems back online.