Digital Transformation Minister Mykhailo Fedorov said another distributed “mass DDoS (denial-of-service) attack’ hit the country about 4pm on Wednesday (1am Thursday AEDT).
On Telegram, he said the websites of the Verkhovna Rada national Parliament, the Cabinet of Ministers and the Ministry of Foreign Affairs had all been affected.
All three websites were still inaccessible more than an hour later.
Mr Federov last week labelled a high-volume cyber attack that temporarily blocked access to defence agencies and banks as “the largest [such attack] in the history of Ukraine”.
The Ukrainian Information Ministry blamed Russia for that attack.
There is no specific evidence that Moscow is behind the latest attacks.
Australia and Germany both earlier warned they were preparing for possible cyber attacks, after laying sanctions on Russia for moving troops into rebel-held areas of eastern Ukraine.
Russian President Vladimir Putin had early recognised the so-called Donetsk and Luhansk people’s republics, which are part of Ukraine, as independent territories and announced he would send in troops as “peacekeepers”.
Multiple Western leaders have described the moves, which came as more than 150,000 Russian troops gathered around the Ukraine border on three sides, as an “invasion”.
Home Affairs Minister Karen Andrews said discussions included cyber security.
“We are concerned about protecting Australia’s interests and we are concerned about the potential for a cyber attack, particularly on our critical infrastructure in Australia,” Ms Andrews said.
