In this photo taken on Tuesday, Feb. 12, 2019, Serhii Demediuk, the head of Ukraine's national CyberPolice unit, talks during an interview with The Associated Press in Kiev, Ukraine, Tuesday, Feb. 12, 2019. Russian hackers are intensifying attacks on the eve of presidential elections in Ukraine, according to the head of Ukraine's cyberpolice Serhii Demediuk. (AP Photo/Efrem Lukatsky)

In this photo taken on Tuesday, Feb. 12, 2019, Serhii Demediuk, the head of Ukraine's national CyberPolice unit, talks during an interview with The Associated Press in Kiev, Ukraine, Tuesday, Feb. 12, 2019. Russian hackers are intensifying attacks on the eve of presidential elections in Ukraine, according to the head of Ukraine's cyberpolice Serhii Demediuk. (AP Photo/Efrem Lukatsky)

In this photo taken on Tuesday, Feb. 12, 2019, Serhii Demediuk, the head of Ukraine's national CyberPolice unit, talks during an interview with The Associated Press in Kiev, Ukraine, Tuesday, Feb. 12, 2019. Russian hackers are intensifying attacks on the eve of presidential elections in Ukraine, according to the head of Ukraine's cyberpolice Serhii Demediuk. (AP Photo/Efrem Lukatsky)

In this photo taken on Tuesday, Feb. 12, 2019, Serhii Demediuk, the head of Ukraine's national CyberPolice unit, talks during an interview with The Associated Press in Kiev, Ukraine, Tuesday, Feb. 12, 2019. Russian hackers are intensifying attacks on the eve of presidential elections in Ukraine, according to the head of Ukraine's cyberpolice Serhii Demediuk. (AP Photo/Efrem Lukatsky)