Ukrainian private and state-owned companies underwent a massive hacker attack. This is reported by domestic media.

In the central offices of Ukrenergo and DTEK, computers are struck by an unknown virus and went out of order, 112 Ukraine reports.

"100% of computers are amazed and do not work at 11:40 today," Ukrenergo. According to the publication, a similar situation - in DTEK.

Interfax-Ukraine reports on hacker attack on Kyivenergo.

"We were attacked by hackers. Two hours ago we had to turn off all the computers, we are waiting for permission to be included from the security service, "the company said..

Earlier today, the National Bank reported on problems in the work of financial institutions.

The attack also affected the systems of the largest postal operators, writes Liga. Net. The press service of Novaya Pochta confirmed the fact of cyber attack. The company site does not work.

IT companies and IT professionals are working to eliminate the consequences of an emergency attack.

"We have all admins from 4 am on their feet. This in history has not yet been. Thousands of companies were attacked. Payments in banks are frozen in the morning, "- said one of the representatives of the IT market.

According to experts, the virus is called DOS / Petya.

"Across the country, the attack, not only the financial sector. Understand. An attempt was made to use this malicious software already, "said SEO CyS Centrum LLC (private center for analysis and counteraction to cyberuroses), Nikolai Koval.

Recall, December 17, 2016 in Kiev, there were interruptions in electricity due to a failure at one of the substations. In some parts of the Ukrainian capital, electricity was not about an hour and a half. In Ukrenergo they are connected with power outages with hacker attacks.