A decryption tool has been made available to Irish authorities that may help to restore the HSE's computer systems.
The ransomware gang behind the cyberattack has provided the key, but the Government says it's still assessing if it's genuine.
Work is underway to ensure the tool will help restore the systems "rather than cause further harm".
They've reiterated they have "not paid a ransom and will not pay a ransom".
In a statement, the Government said: "While this is, of course, an encouraging development the detailed programme of work to repair and restore the IT systems still needs to be carried out.
"The teams of people engaged in this important work will continue to carry it out.
"Every effort is being made to restore important aspects of the HSE’s IT infrastructure as soon as possible and the focus remains very firmly on restoring medical services for the many thousands of patients in need of them."
A Garda investigation into the cyberattack is continuing.
Earlier, Bloomberg reported that the hackers behind the cyberattack had threatened to begin releasing patient data by Monday if no ransom is paid.
Meanwhile, HSE boss Paul Reid said the impact of the attack will be felt for many, many weeks.
