The Russian military intelligence agency accused of the attempted assassination of former spy Sergei Skripal has carried out a swathe of attacks in the UK and abroad on political institutions, financial systems, transport networks and the media, according to the British government.

This secret international cyberwar has included the targeting of the US presidential elections which brought Donald Trump to power, according to a new report from the National Cyber Security Centre (NCSC), as well the anti-doping watchdog in world sport.

The report follows the statement by Theresa May that Britain and allied countries will work together to expose the work of the GRU and the methods it uses.

One of the two Russians accused by Britain of the attempted assassination of Skripal and his daughter Yulia in Salisbury, with the poison novichok, has been named as a GRU colonel. The Kremlin has denied the link, and denied any involvement in the poisoning of the former Russian spy.

This new document has been put together by the NCSC, working with other UK and European intelligence agencies, and the NSA and FBI in the United States.

Although there were allegations of Russian culpability over many episodes of the organised hacking, investigations have shown that the GRU are the main perpetrators. The trail shows, say security officials, that the organisation has become the Kremlin’s chosen clandestine weapon in pursuing its geopolitical goals.

The GRU, according to the NCSC, is associated with a number of hacking groups whose names are used as “flags of convenience” including Fancy Bear: Sofacy; Pawnstorm: Sednit: CyberCaliphate: Cyber Berkut: Voodoo Bear: BlackEnergy Actors: Strontium: Tsar Team and Sandworm.

In April this year the NCSC, the FBI and the US Department of Homeland Security issued a joint alert about Russian cyber activity aimed at both the public sector, infrastructure and internet service providers.

Ciaran Martin, the head of the NCSC said at the time: “Russia is our most capable hostile adversary in cyberspace so tackling them is a major priority.

“This is the first time that in attributing a cyberattack to Russia, the US and the UK have, at the same time, issued joint advice to industry about how to manage the risks from the attack. It marks an important step in our fight back against state-sponsored aggression in cyberspace.”

One of the biggest cyberattacks affecting this country took place in October last year when personal details of almost 700,000 UK nationals were accessed following the hacking of the US credit monitoring firm Equifax.

At the same time attacks took place in Ukraine, a state with which Moscow is locked in confrontation, with the metro system in Kiev and Odessa airport hit, along with the synchronised use of malware in Bulgaria, Turkey, Japan and Russia itself.

This pattern of behaviour demonstrates their desire to operate without regard to international law <p>Foreign Secretary Jeremy Hunt</p>

In the summer of 2015, a British television company was targeted and information from multiple email accounts stolen.

Four months earlier the French television station TV5Monde was taken off air when malicious software destroyed the network system.

A group calling itself the Cyber Caliphate claimed responsibility at the time but the attack was traced back to the Russian hacking group APT 28, which has become better known as Fancy Bear, one of the GRU affiliates.

Two months after that, a cyberattack targeted the financial and energy sector in Ukraine, but soon spread further, affecting other European and also Russian businesses. The source of the malware was traced back, say British security officials, to the GRU.

In September 2016, Wada (the World Anti-Doping Agency) was hacked, and data pertaining to athletes, including medical details, stolen. The breach was carried out by Fancy Bear. The information, which was disseminated on Fancy Bear’s website, involved 41 athletes from 13 countries, including six from the UK and 14 sports altogether.

The hacking took place after the Russian branch of the organisation was suspended following revelations about a state-sponsored drugs programme. Russia is now about to be readmitted to the organisation, a move that has led to the resignation of a member of Wada’s committee and threats to do so from others.

The allegations of Russian interference in the 2016 US presidential election has hung over the Trump White House, with investigations being carried out by the special counsel, Robert Mueller, with the hacking of the Democratic National Committee (DNC) being one of key issues.

'Nothing criminal' about UK Skripal suspects says Putin

A vast amount of material, including Hilary Clinton’s emails, were made public, some of it through Julian Assange’s Wikileaks site. Twelve Russian nationals, allegedly members of the GRU, have been indicted over the cyberattack by Mr Mueller.

Two GRU teams, Units 26165 and 74455, both located in Moscow, allegedly carried out the campaign, beginning in early 2016, according to the indictment.

One of the intelligence officers, Senior Lt Aleksey Lukashev, used various online fake personas, including “Den Katenberg” and “Yuliana Martynova”, to craft “spearphishing” emails to gather the information.

Captain Nikolay Kozachek, allegedly crafted the X-Agent malware used to hack the Democratic Congressional Campaign Committee and DNC networks in April 2016. Unit 74455, also known as the Main Centre for Special Technology, engineered the release of the stolen documents, according to the indictment.

In a statement in response to the NCSC’s report, the 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.