Russia's Federal Security Service, the FSB, has claimed that a "coordinated attack" had seen spyware infect the computer networks of around 20 state agencies, defence companies and other organisations in the county.
"Information technology resources of government agencies, scientific and military institutions, defence industry companies and other entities involved in crucial infrastructure have been infected," the FSB said in a statement on its website. The agency did not speculate on who was behind the attacks.
A source told the state-run TASS news agency that "it was a targeted virus, spread, planned and made professionally". They added that it was similar to software used in earlier cyberespionage in both Russia and around the globe.
"The newest sets of the said software are made individually for every 'victim', on the basis of unique features of attacked machines," the source added.
Like many viruses it is spread via a malicious attachment in an email which then "launches the necessary becomes able to intercept the network traffic, listen to it, make screenshots, turn on web cameras and PC microphones, mobile devices, to record audio and video files, reports on use of keys and so forth", the source added.
The FSB's announcement follows a spate of reports about cyberattacks in the US, including one on the fundraising committee for Democratic candidates for the US House of Representatives that led to the publication of thousands of emails on WikiLeaks.
They showed officials strategising against Hillary Clinton's rival Bernie Sanders in his campaign for the Democratic nomination, at a time when the Democratic National Committee claimed it was neutral in the race.
However, both US officials and cybersecurity experts have said the hacking likely originated in Russia, opening the possibility that it was the result of an espionage operation.
The Clinton campaign alleges that the leak was a deliberate attempt to damage Hillary Clinton's campaign and help her Republican rival Donald Trump, who some experts believe the Kremlin prefers to be the next US president.
The hacking claims have been strongly denied by Russia.