Hackers with ties to Russia, China and Iran are attempting to spy on people and groups involved with the US 2020 presidential election, Microsoft has announced.
The Russian group which hacked the 2016 Democratic campaign is again involved in cyber-attacks, said the tech giants.
Both President Donald Trump and Democrat Joe Biden’s campaigns are being targeted.
Russian hackers from the Strontium group have targeted more than 200 organisations, many of which are linked to US political parties – both Republicans and Democrats, Microsoft said in a statement.
“Similar to what we observed in 2016, Strontium is launching campaigns to harvest people’s log-in credentials or compromise their accounts, presumably to aid in intelligence gathering or disruption operations,” said Tom Burt, a Microsoft vice-president in charge of customer security and trust.
The firm said Chinese hackers had launched attacks targeting individuals connected to Mr Biden’s campaign, while Iranian hackers had continued efforts targeting people associated with the Trump campaign.
Most of the cyber-attacks had not been successful, according to Microsoft. The attacks have also not been launched on groups that handle the voting systems themselves.
“What we’ve seen is consistent with previous attack patterns that not only target candidates and campaign staffers but also those they consult on key issues,” Mr Burt said.
“These activities highlight the need for people and organisations involved in the political process to take advantage of free and low-cost security tools to protect themselves as we get closer to election day.”
It added that “prominent individuals” in the international affairs community, academic institutions and policy organisations have been targeted by the Chinese hacking group, known as Zirconium.