Update 7.10pm: It has been confirmed a HSE-funded healthcare centre in Wexford has been affected by the global cyber attack.
The tech expert who stopped the attack in its tracks has identified Ireland as one of the affected countries.
Over 100 nations worldwide are working to combat the WANNACRY virus.
Here the Department of Communications has confirmed a number of Irish locations were targeted but only the Wexford incident was active and this has now been addressed.
Update 4.30pm: Europol said a major cyber attack is on an "unprecedented" level.
The EU law enforcement agency also says it will require a "complex international investigation to identify the culprits".
The Government says the National Cyber Security Centre is in close contact with the Gardaí and HSE on the issue.
The attack has paralysed much of the NHS in the UK and has affected more than 70 countries worldwide.
Minister for Communications Denis Naughten said the situation could still escalate here and encouraged people to take preventative measures.
“The likelihood is that next week we may have other attacks recorded because there is a lot of legacy equipment, not just in the public sector but also in the private sector.
“What we are trying to do is make people aware of that and ensure that they download the required patch and that they keep software updated by downloading patches as they are required.”
Update: 11am: The Government is continuing to monitor a major cyber attack that is affecting up to 100 countries across the globe.
The HSE has taken measures to protect its IT network after the NHS in the UK was targeted by the ransomeware virus.
Major businesses and corporations are being targeted by the threat which targets files and demands that a payment be made in order to unlock them.
The government has said there are no reports of any Irish companies caught up in the attack so far.
Minister for Communications Denis Naughten said it is an unprecedented attack: "We're working quite closely with our European counterparts and an Garda Siochana.
"I have spoken already this morning with them, the Tanaiste and the Minister for Health aswell and I suppose look what what is happening at the moment, we haven't seen anything of this scale before."
Earlier: Gardaí say there are no reports of any Irish victims of the latest worldwide cyber attack.
The HSE has taken precautionary measures to protect their IT systems by removing all external access to the network.
Dozens of countries were hit with a huge cyberextortion attack at a multitude of hospitals, companies and government agencies.
The attack, that saw computers locked and users' files held for ransom, was believed to the biggest ever recorded.
The malicious software behind the onslaught appeared to exploit a vulnerability in Microsoft Windows that was supposedly identified by the US National Security Agency for its own intelligence-gathering purposes and was later leaked to the internet.
The UK's National Health Service fell victim, its hospitals forced to close wards and emergency rooms and turn away patients.
Russia appeared to be the hardest hit, according to security experts, with the country's Interior Ministry confirming it was struck.
All told, several cybersecurity firms said they had identified the malicious software, which so far has been responsible for tens of thousands of attacks, in more than 60 countries.
That includes the United States, although its effects there did not appear to be widespread, at least initially.
The attack infected computers with what is known as "ransomware", software that locks up the user's data and flashes a message demanding payment to release it.
In the US, FedEx reported its Windows computers were "experiencing interference" from malware, but would not say if it had been hit by ransomware.
Mikko Hypponen, chief research officer at the Helsinki-based cybersecurity company F-Secure, called the attack "the biggest ransomware outbreak in history".
Security experts said the attack appeared to be caused by a self-replicating piece of software that enters companies and organisations when employees click on email attachments, then spreads quickly internally from computer to computer when employees share documents and other files.
Its ransom demands start at 300 dollars and increase after two hours to 400, 500 and then 600 dollars, said Kurt Baumgartner, a security researcher at Kaspersky Lab.
Affected users can restore their files from backups, if they have them, or pay the ransom; otherwise they risk losing their data entirely.
Chris Wysopal of the software security firm Veracode said criminal organisations were probably behind the attack, given how quickly the malware spread.
"For so many organisations in the same day to be hit, this is unprecedented," he said.
The security holes it exploits were disclosed several weeks ago by TheShadowBrokers, a group that has published what it says are hacking tools used by the NSA as part of its intelligence-gathering.
Shortly after that disclosure, Microsoft announced it had already issued software "patches" for those holes.
But many companies and individuals have not installed the fixes yet or are using older versions of Windows that Microsoft no longer supports and did not fix.
By Kaspersky Lab's count, the malware struck at least 74 countries.
In addition to Russia, the biggest targets appeared to be Ukraine and India, nations where it is common to find older, unpatched versions of Windows in use, according to the security firm.
Spain, meanwhile, took steps to protect critical infrastructure in response to the attack.
Authorities said they were communicating with more than 100 energy, transportation, telecommunications and financial services providers about the attack.
Spain's Telefonica, a global broadband and telecommunications company, was among the companies hit.
Ransomware attacks are on the rise around the world.
In 2016, Hollywood Presbyterian Medical Centre in California said it had paid a 17,000 dollars ransom to regain control of its computers from hackers.