The National Cyber Authority on Thursday said that a cyberattack targeting Israeli hospitals was smaller than previously believed and that it was not in fact connected to a ransomware virus affecting computers worldwide, despite earlier reports.

While eight hospitals were originally thought to have been targeted, it turned out that only two hospitals were affected, with the other six hospitals having issued false warnings of attacks on their computer systems, the cyber authority said in a statement.

It also said that the incident was not linked to a worldwide ransomware attack targeting computer networks this week — namely in Ukraine and Russia — and emphasized that no damage was caused. Institutions targeted were continuing their operations as usual, it added.

In an earlier statement, the National Cyber Authority said that the event was thwarted and dealt with “immediately,” without revealing the names of the institutions attacked.

The hack, which occurred on the night between Wednesday and Thursday, infected a number of computers but was dealt with immediately by IT security officials at the sites, the Prime Minister’s Office said in a statement.

A monitor making sure vital signs of the patient are in check during open heart surgery at Wolfson Medical Center in Holon , September 12, 2011. (Illustrative photo: Nati Shohat/Flash90)

A monitor making sure vital signs of the patient are in check during open heart surgery at Wolfson Medical Center in Holon, September 12, 2011. (Illustrative photo: Nati Shohat/Flash90)

The second statement didn’t address reports that the Israeli offices of shipping company Maersk, the pharma company Merck and other small and medium-sized offices were targeted.

The latest attack came as top global cybersecurity officials, gathered in Tel Aviv for the annual Cyber Week conference, were warning that hackers are winning the battle in the cyber war, as more and more devices come online and as protections remain painfully inadequate.

Israel was thought to be largely spared by the latest global wave of cyberattacks that began in Russia and Ukraine on Tuesday, which wreaked havoc on government and corporate computer systems as it spread around the world.

Prime Minister Benjamin Netanyahu said earlier this week that every month Israel experiences dozens of cyberattacks at a national level, and at any given moment there are probably three to five attacks on a national level that emanate from various sources.