According to the the UK's National Cyber Security Centre, GRU targeted firms in Russia and Ukraine, the US Democratic Party, and a British TV network.

It said that the GRU also attacked World Anti-Doping Agency computers, revealing 'how British cyclists Sir Bradley Wiggins and Chris Froome had used banned substances for legitimate medical reasons', the BBC reported.

Earlier this month, an investigative website also identified Russian double agent Sergei Skripal's attacker as a GRU personnel.

Skripal and his daughter Yulia were attacked with a nerve agent in the United Kingdom's Salisbury region earlier this year.

However, they both survived. 

Bellingcat, the website, said that the attacker was decorated Russian military officer Colonel Anatoliy Chepiga.

Chepiga allegedly visited the UK under the guise of Ruslan Boshirov.

Reacting strongly towards Russia, British Foreign Secretary Jeremy Hunt said: "The GRU's actions are reckless and indiscriminate: they try to undermine and interfere in elections in other countries; they are even prepared to damage Russian companies and Russian citizens."

"This pattern of behaviour demonstrates their desire to operate without regard to international law or established norms and to do so with a feeling of impunity and without consequences.

"Our message is clear: together with our allies, we will expose and respond to the GRU's attempts to undermine international stability," Hunt said.