Ukraine’s national bank, state power company and largest airport are among the targets of a huge cyber attack on government infrastructure.
Rozenko Pavlo, the deputy Prime Minister, said he and other members of the Ukrainian government were unable to access their computers.
“We also have a network 'down',” he wrote. “This image is being displayed by all computers of the government.”
The photo showed his PC displaying a message claiming a disk “contains errors and needs to be prepared”, urging the user not to turn it off.
Images from other affected computers and disabled cash points showed what appeared to be ransomware, demanding a payment of $300 (£235) in Bitcoin to re-gain access to encrypted files.
Analysts said the virus, named Petrwrap or Petya, appeared to work similarly to the WannaCry ransomware that infected more than 230,000 computers in 150 countries last month.
Ukrainian state-run aircraft manufacturer Antonov was among the companies hit, along with power distributorUkrenergo, which said the attack did not affect power supplies.
The National Bank of Ukraine said an “unknown virus” was to blame, saying several unnamed Ukrainian banks were affected along with financial firms.
“As a result of cyber attacks, these banks have difficulties with customer service and banking operations,” a statement said.
No shots fired, no soldiers parachuting in, no tanks rolling across the roads, but still billions in damage. And there really shouldn't be any question as to who's behind it.
The secretary of Ukraine's security council said there were signs of Russian involvement in a wave of cyberattacks that hit Ukrainian institutions on Tuesday, including banks and the state power distributor.
"Already on first analysis of the virus it is possible to talk of Russian fingerprints," the National Security and Defense Council quoted Secretary Oleksandr Turchynov as saying.
This is how wars will be fought going forward: critical transportation, corporate, medical, economic, logistic, and electrical infrastructure systems all crashed at once. Of course, there will be plenty of old fashioned shooting and bombing too, but the era of including a cyber component of warfare in skirmishes between nation-states is upon us.
After all, our good friends the Russians know damn good and well that internet warfare works.
Just ask Donald Trump.