"From May 25 to June 6, the Ukrainian Security Service, in close cooperation with foreign partners, has stopped the use of the Ukrainian network infrastructure for targeted dissemination of malicious software by the Russian special services in order to destroy information networks of the critical infrastructure facilities of our state and other countries of the world," the report says.

Read alsoPetya.A ransomware map: Ukraine falls under most massive attackIt is noted that, together with foreign partners, the work of the extensive international network infrastructure, which was built by the special services of the Russian Federation, has been stopped.

Targeted cyber attacks (the so-called APT-attacks – Advanced Persistent Threat), as well as the infecting of critical infrastructure objects of Ukraine and other countries with special types of malicious computer programs, were secretly carried out with the help of this infrastructure and with the use of server equipment, including the Ukrainian hosting.

Read alsoUN: Money not likely main motive of cyber attackers"During the searches, the law enforcement officers have seized server equipment that was involved in the cyber attack system by the special services of the Russian Federation. The investigation is underway. Those involved in illegal activities are being identified, as well as information that circulated in the cyber infrastructure," the press service said.

As UNIAN reported earlier, on June 27, Ukrainian banks, energy companies, state-owned Internet resources and local networks, as well as Ukrainian media and other large enterprises underwent a mass hacker attack spreading the Petya.A ransomware, which blocked the operation of computer systems.

The virus was also spreading in Russia, England, India and other countries of Europe and Asia.