"Such activities...threaten our integrity and security, democratic values and principles and the core functioning of our democracies," Josep Borrell said.
The National Security Agency said the attacks by operatives were linked to the Russian military intelligence agency.
The former Russian president said he is pessimistic a Biden presidency would mean better ties between Washington and the Kremlin.
Chaos over mail-in ballots and distrust of the results could trigger an existential crisis for American democracy.
On Tuesday, the DOJ, DOD, DHS, DNI, FBI, NSA, and CISA released a joint statement on 2020 election security, warning that "Russia, China, Iran, and other foreign malicious actors all will seek to interfere in the voting process or influence voter perceptions."
Former Special Counsel Robert Mueller's testimony Wednesday before two House committees stamped out Attorney General William Barr's misleading three-page summary.
Cyberhacking has become more prevalent in today's society due to the alleged infiltration of our voting systems by Russian Intelligence in the 2016 Presidential Election. Expert Richard Clarke explains how the U.S. will fare against cyberhacking in next year's election.
It is not just the election that Russia has been accused of hacking.
Russian hackers have been trying to break into Senate email accounts as part of a broader influence campaign, cybersecurity experts said Friday.
Moscow's top diplomat joked that Russia had a "tough year" interfering in every election in the world, regrets it so far failed to topple the Japanese emperor.
No evidence has surfaced that Trump officials notified the FBI about contacts with the Russians, as they were advised to do.
Special counsel Robert Mueller has announced his first charges, but the investigations by lawmakers are mired in partisan politics.
After being called out in a speech at a cybersecurity conference, the Russian hackers have been targeting experts with emails mimicking invitations for this year's event.
The U.S. was accused of abducting Russian citizens around the world, including the latest arrest of a suspected cyber thief.
Senators were left frustrated by the Department of Homeland Security's refusal.
Russia has come up with a digital-age update to traditional spying methods.
"Only God knows our destiny—yours and mine," Putin said.
Much of the West's opposition to Russia comes from a purely ideological root.
The president's tweets 'tell the story' of how he seeks to deflect attention, House Intelligence Committee Democrat says.
The former national security advisor had to amend his disclosure after leaving off payments for speaking engagements to Russian entities.
Trump and associates' murky financial dealings deserve greater scrutiny.