Ukraine's State Security Service (SBU) said on March 16 it had prevented a large-scale cyberattack by Russian hackers targeting classified government data.
The SBU said the aim was to "get access to classified data of the highest institutions of state power of Ukraine" and accused the Russian Federal Security Service (FSB) of being behind the hackers who it said had carried the attack.
Kyiv has previously accused Moscow of orchestrating large cyberattacks as part of a "hybrid war" against Ukraine, but Russia denies this. The FSB did not immediately comment on the latest accusation.
The SBU did not say whether any damage had been caused in the latest incident, which it blamed on a FSB-controlled hacker group it identified as Armageddon.
In February, Ukrainian cyberauthorities accused unnamed Russian Internet networks of attacks on Ukrainian security and defense websites, and of trying to disseminate malicious documents through a Web-based system.
Relations between Kyiv and Moscow have been strained since Russia illegally took control of Crimea from Ukraine seven years ago after sending in troops, seizing key facilities in February 2014, and staging a referendum weeks later that was dismissed as illegitimate by at least 100 countries.
Moscow also backs separatists in a war against Ukrainian government forces that has killed more than 13,000 people in eastern Ukraine since April 2014.
