A classified intelligence report obtained by The Intercept shows the latest information acquired by the agency about a months-long Russian intelligence cyber effort against elements of the U.S. election and voting infrastructure.

The report, dated May 5, 2017, indicates that Russian hacking may have penetrated further into US voting systems than was previously understood and the attacks were conducted by the Russian General Staff Main Intelligence Directorate, or GRU.

One hack was in August 2016, to obtain information on elections-related software and hardware solutions. The idea was to launch a voter registration-themed spear-phishing campaign targeting US local government organisations.

All this is at odds with Russian President Vladimir Putin’s denial last week that Russia had interfered in foreign elections. He claimed that Russia never engaged in that on a state level, and had no intention of doing so.

Putin, who had previously issued blanket denials that any such Russian meddling occurred, for the first time floated the possibility that freelance Russian hackers with “patriotic leanings” may have been responsible. The NSA report, on the contrary, displays no doubt that the cyber assault was carried out by the GRU.

The NSA has now learned, that Russian government hackers, part of a team with a “cyber espionage mandate specifically directed at U.S. and foreign elections, focused on parts of the system directly connected to the voter registration process, including a private sector manufacturer of devices that maintain and verify the voter rolls.