Software for hacker attacks on Ukrainian companies was designed in Russia and attacks were planned for at least six months, Head of the information security service of the National Security and Defense Council (NSDC) of Ukraine Valentyn Petrov has said.

"This process lasted for at least six months. Not only Ukrainian energy companies (this is only the tip of the iceberg) and other large enterprises and one of the national television channels were attacked," he said in an interview with Germany's ZDF, the NSDC press service reported on Wednesday.

Petrov said that Ukrainian specialists revealed that hacker attacks at Ukrainian energy companies are tracking to Russian servers: "There are signs that Russian software designers participated in designing different types of software for this," he said.

He said that when Ukrainian criminalists analyzed the virus they determined it was likely that the virus was designed and had all settings to work with Cyrillic alphabet.

He also said that the virus prototype used against Ukrainian energy companies was actively spread by a Russian in 2007 at one of the computer forums.

"He was spreading software at the specialized forum, which later turned out to be a virus to attack Ukrainian companies. The Russian citizen created the virus," Petrov said.

The fact that temporary settings on the PC where the virus was created coincide with the Moscow and St. Petersburg time zone is evidence the virus was created in Russia, he said.

"Attacks at energy companies are a wake-up call for us, and it is more a wake-up call for European countries and countries where information technologies are developed better than in Ukraine. The Russian cyber-attack demonstrates Russians have cyber weapons which threaten the security of western countries," Petrov said.