technicians Kiev airport
© Valentyn Ogirenko (Reuters)Technicians work on a flight timetable for Kyiv's main airport during a global cyberattack on June 27, 2017.
Ukraine's security agency said it has thwarted a massive cyberattack and blamed Russia for the attempted attack that targeted the country's court system.

The Security Service of Ukraine said in a statement December 4 that hackers used falsified accounting documents to target computers of the country's judiciary system.

The service, known as the SBU, said the alleged hacking was "massive" but provided no detail about the extent, timing, or severity of the hacks.

Ukraine has been hit regularly by major cyberattacks and hacking attempts since 2014 when Russia annexed Crimea and Russian-backed militants launched a war in eastern regions that has killed more than 10,000 people.

In December 2015, the country's electrical grid was targeted with coordinated cyberattacks that caused major disruptions in power supplies.

The SBU blamed Russia. However, U.S. government agencies, who later pinpointed the intrusions, stopped short of blaming Moscow.

Private researchers, however, blamed a Russian hacking group that is believed to have links to Russian security agencies.