Dutch security services expelled four Russians over a cyber plot in April targeting the global chemical weapons watchdog, officials said.
The operation by Russia’s GRU military intelligence allegedly targeted the Organisation for the Prevention of Chemical Weapons (OPCW) in The Hague.
The OPCW has been probing the chemical attack on a Russian ex-spy in the UK.
The allegations are part of an organised push-back against alleged Russian cyber attacks around the world.
Earlier, UK government accused the GRU of being behind four high-profile cyber-attacks whose targets included included firms in Russia and Ukraine; the US Democratic Party; and a small TV network in the UK.
Russia has called the accusations a “diabolical cocktail” of allegations.
‘Closed access hack’
The four suspects identified by Dutch officials had diplomatic passports and included an IT expert as well as support agents, officials said.
They hired a car and were seen to be scouting to carry out a closed access hack operation targeting the OPCW’s wifi network.
Equipment in the car boot was pointed at the OPCW and was being used to intercept login details, Maj Gen Onno Eichelsheim from the Dutch MIVD intelligence service said.
When the men were intercepted they tried to destroy one of the mobile phones they were carrying.
What was on their computer?
A laptop seized from the suspects was found to have been used in Brazil, Switzerland and Malaysia.
In Malaysia it was used to target the investigation into the downing of Malaysia Airlines flight MH-17 over rebel-held territory in eastern Ukraine in 2014, killing all 298 people on board
Earlier this year Dutch-led international investigators concluded that the missile belonged to a Russian brigade. Russia has denied any involvement in the plane’s destruction.
Data from the laptop showed it was also present in the Swiss city of Lausanne where it was linked to the hacking of a laptop belonging to the World Anti-Doping Agency (Wada), which has exposed doping by Russian athletes.
What is the GRU?
The GRU, also known as the Main Intelligence Directorate, is the intelligence arm of the Russian military.
It is different to the former KGB (now known as the SVR and FSB) as it conducts undercover military operations and collects intelligence operations around the globe.
In recent years the GRU has been accused of undercover involvement in the conflict in Ukraine, which saw the Russian annexation of Crimea in 2014.
It is believed that the two men accused of poisoning Russian ex-spy Sergei Skripal and his daughter Yulia, named as Alexander Petrov and Ruslan Boshirov, were GRU agents.