Employees talk in front of screens at the Ukrainian Security Service headquarters (SBU) in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

Employees talk in front of screens at the Ukrainian Security Service headquarters (SBU) in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

Employees talk in front of screens at the Ukrainian Security Service headquarters (SBU) in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

Employees talk in front of screens at the Ukrainian Security Service headquarters (SBU) in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

An employee shows a screen at the Ukrainian Security Service headquarters (SBU) in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

Oleksandr Klymchuk, Head of the Information Security Department of the Ukrainian Security Service (SBU) speaks during an interview with AFP in front of screens at the SBU headquarters in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

Oleksandr Klymchuk, Head of the Information Security Department of the Ukrainian Security Service (SBU) speaks during an interview with AFP in front of screens at the SBU headquarters in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)

A photo shows a fragment of a screen at the Ukrainian Security Service headquarters in Kiev on March 6, 2019 during the joint EU-Ukraine cyber security drills organized by the Central Election Commission safety ahead of the March 31 Presidential election. - At the headquarters of Ukraine's SBU security service more than a dozen local and Western security experts watch a simulated foreign cyber attack on several big screens ahead of this month's presidential vote. During the joint EU-Ukraine cyber security drills the Westerners pretend to be hackers attacking the country's central election commission, while the Ukrainians seek to neutralise them. (Photo by Sergei SUPINSKY / AFP)