The same Russian military intelligence outfit that hacked the Democrats in 2016 has attempted similar intrusions into the computer systems of more than 200 organisations including political parties and consultants, Microsoft said on Thursday.
Those efforts appear to be part of a broader increase in targeting of US political campaigns and related groups, the company said. "What we've seen is consistent with previous attack patterns that not only target candidates and campaign staffers but also those who they consult on key issues," Tom Burt, a Microsoft vice president, said in a blog post.
Most of the infiltration attempts by Russian, Chinese and Iranian agents were halted by Microsoft security software and the targets notified, he said. The company would not comment on who may have been successfully hacked or the impact.
Although US intelligence officials said last month that the Russians favour President Donald Trump and the Chinese prefer former Vice-President Joe Biden, the Democratic challenger, Microsoft noted Thursday that Chinese state-backed hackers have targeted "high-profile individuals associated with the election," including people associated with the Biden campaign.
China is largely an espionage threat, however, while Russia steals data and weaponises it.
Microsoft did not assess which foreign adversary poses the greater threat to the integrity of the November presidential election. The consensus among cybersecurity experts is that Russian interference is the gravest. Senior Trump administration officials have disputed that, although without offering any evidence.
"This is the actor from 2016, potentially conducting business as usual," said John Hultquist, director of intelligence analysis at the top cybersecurity firm FireEye. "We believe that Russian military intelligence continues to pose the greatest threat to the democratic process."
The Microsoft post shows that Russian military intelligence continues to pursue election-related targets undeterred by US indictments, sanctions and other countermeasures, Hultquist said. It interfered in the 2016 campaign seeking to benefit the Trump campaign by hacking the Democratic National Committee and emails of John Podesta, the campaign manager of Hillary Clinton, and dumping embarrassing material online, congressional and FBI investigators have found.
The same GRU military intelligence unit, known as Fancy Bear, that Microsoft identifies as being behind the current election-related activity also broke into voter registration databases in at least three states in 2016, though there is no evidence it tried to interfere with voting.
Microsoft, which has visibility into these efforts because its software is both ubiquitous and highly rated for security, did not address whether US officials who manage elections or operate voting systems have been targeted by state-backed hackers this year. US intelligence officials say they have so far not seen no evidence of that.
Thomas Rid, a Johns Hopkins geopolitics expert, said he was disappointed by Microsoft's refusal to differentiate threat level by state actor. "They're lumping in actors that operate in a very different fashion, probably to make this sound more bipartisan," he said. "I just don't understand why."
Microsoft said in the past year it has observed attempts by Fancy Bear to break into the accounts of people directly and indirectly affiliated with the US election, including consultants serving Republican and Democratic campaigns and national and state party organisations - more than 200 groups in all.
Also targeted was the center-right European People's Party, the largest grouping in the European Parliament. A party spokesperson said the hacking attempts were unsuccessful. The German Marshall Fund of the United States, a think tank, was another target. A spokesperson said there was no evidence of intrusion.
Microsoft did not say whether Russian hackers had attempted to break into the Biden campaign but did say that Chinese hackers from the state-backed group known as Hurricane Panda "appears to have indirectly and unsuccessfully" targeted the Biden campaign through non-campaign email accounts belonging to people affiliated with it.
The Biden campaign did not confirm the attempt, although it said in a statement that it was aware of the Microsoft report.
The blog post said Iranian state-backed hackers have unsuccessfully tried to log into accounts of Trump campaign and administration officials between May and June of this year. "We are a large target, so it is not surprising to see malicious activity directed at the campaign or our staff," Trump campaign deputy press secretary Thea McDonald said. She declined further comment.
Tim Murtaugh, the campaign's communications director, said: "President Trump will beat Joe Biden fair and square and we don't need or want any foreign interference."
In June, Google disclosed that Hurricane Panda had targeted Trump campaign staffers while Iranian hackers had attempted to breach accounts of Biden campaign workers. Such phishing attempts typically involve forged emails with links designed to harvest passwords or infect devices with malware.
Although both Attorney General William Barr and National Security Advisor Robert O'Brien have both said China represents the greatest threat to U.S. elections, the only mention of a Trump administration official targeted by Chinese hackers is "at least one prominent individual formerly associated with" the administration.
Graham Brookie, director of digital forensic research at The Atlantic Council, disputes Barr and O'Brien's claim that China poses the greater threat to this year's election. His lab is at the forefront of unearthing and publicising Russian disinformation campaigns.
Brookie confirmed that his employer was among targets of Hurricane Panda but said there was no evidence the hacking attempts, which he said were unsuccessful, had anything to do with the 2020 election.
"We have every indication that this was an instance of cyber-espionage, information gathering, as opposed to electoral interference," he said.