Officials say the U.S. election system is so secure that no foreign nation could tamper with the results on a scale necessary to change the outcome. However, authoritarian adversaries have harnessed disinformation and cyber espionage to target campaigns and voters while fueling mistrust and discord.

Here’s what you need to know as the presidential election approaches:

Russia is the most active and sophisticated nation working to manipulate the US election, using fake websites, state-controlled media and unknowing Americans to spread misleading and polarizing content designed to undermine confidence in the election .

The Kremlin’s disinformation apparatus deals with controversial issues such as immigration, crime, the economy or disaster relief. The aim is to weaken the US, erode support for Ukraine as it fights Russian invaders and reduce America’s ability to counter Russia’s growing ties to China, North Korea and Iran, officials said.

Intelligence officials and private security analysts have determined that Russia is supporting former President Donald Trump and using disinformation — sometimes generated by artificial intelligence — to smear his Democratic opponent, Vice President Kamala Harris. Trump has praised Russian President Vladimir Putin, suggested cutting off funding to Ukraine and repeatedly criticized the NATO military alliance.

In a particularly bold campaign, Russia put together a video that falsely accused Harris of paralyzing a woman in a car accident years ago. Another video made fictitious allegations against Harris’ partner, Minnesota Gov. Tim Walz.

On Friday, the FBI confirmed Moscow’s role in creating a third video purported to show the destruction of mail-in ballots in Pennsylvania. Local election officials quickly debunked the video as fake.

Russia has also tried to pay off American influencers who spread the Kremlin’s preferred narratives. Last month, US authorities charged two Russian state media employees with funneling $10 million to a Tennessee company to create pro-Russian content. The company then paid several popular right-wing influencers who said they had no idea their work was supported by Russia.

The Moscow campaign will not end on election day. Instead, intelligence officials and private security analysts predict that Russia will exploit claims of election irregularities to suggest that the results cannot be trusted. A recently declassified intelligence memo said Russia could also encourage violent protests after the election.

“Putin’s goal is to foster chaos, division and polarization in our society,” said Michael McFaul, a former US ambassador to Russia who now teaches at Stanford University.

Russia has denied claims it tried to influence the US election. A message left with the Russian embassy in Washington was not immediately returned Saturday.

Iran has been a particularly eager player in foreign interference this year.

He is accused of hacking Trump campaign associates and providing the stolen communications to media organizations and Democrats in hopes of damaging stories that could hurt the Republican’s prospects. Emails dangling dirt were sent to people associated with President Joe Biden’s campaign, but there is no indication that anyone has responded, officials said.

Last month, the Justice Department indicted three Iranian hackers who remain at large, accusing them of a years-long operation that targeted a wide range of victims.

US officials described the attack as part of a larger effort to interfere in an election that Iran perceives as particularly important. Iran, they say, has made clear its opposition to Trump’s campaign. His administration struck a nuclear deal with Iran, reimposed sanctions and ordered the killing of Iranian general Qassem Soleimani, an act that prompted Iranian leaders to vow revenge.

In addition to cyber operations, US officials have repeatedly raised concerns about Iran’s potential to carry out violence on US soil against Trump or other members of his administration. Officials brought charges in 2022 in a foiled Iranian plot to kill Trump’s national security adviser, John Bolton, and this year charged a Pakistani with ties to Iran in a plot to carry out political assassinations in the US, including potential of Trump.

Leaders in Tehran may also seek to encourage violent protests after the election, according to the declassified intelligence memo. Authorities say Iran has also secretly funded and supported U.S. protests over Israel’s war in Gaza.

Iranian authorities have rejected accusations that the country is trying to influence the election. Iran’s mission to the United Nations released a statement this week saying, “Iran has no motive or intention to interfere in the U.S. election.”

US intelligence officials believe China is taking a more neutral stance in the election and focusing on reverse-ballot races, targeting candidates from both parties based on their positions on issues of key importance to Beijing, including support for Taiwan.

But the Chinese government has for years run a sophisticated hacking operation targeting all kinds of Western life and industry that goes far beyond electoral influence.

“From the city council to the president, they want access,” said Adam Darrah, a former CIA political analyst who is now vice president of intelligence at cybersecurity firm ZeroFox, which tracks foreign threats online.

On Friday, news broke that Chinese hackers, as part of a much larger spying effort, had targeted cellphones used by Trump, his running mate JD Vance and people associated with the Harris campaign. It was not immediately clear what data, if any, was accessed.

A spokesman for the Chinese Embassy in Washington said they were not familiar with the details and could not comment, but maintained that China is routinely victimized by cyber attacks and opposes the activity.

Hard. Foreign adversaries, including the same ones now accused of meddling, have sought to interfere in the past several election cycles — with varying degrees of success.

But the US government, accused of relying on intelligence about the extent of Russian interference in the 2016 election, has worked this year to aggressively flag foreign threats as part of an effort to reduce their impact and reassure Americans that the election is safe. .

In 2016, Russian military intelligence officers hacked the email accounts of Hillary Clinton’s campaign chairman and the Democratic Party and released tens of thousands of communications in an effort to boost Trump’s successful presidential campaign.

Russia also engaged that year in a huge but covert social media trolling campaign designed to sow discord on hot-button social issues, divisive the US electoral process and harm Clinton’s bid for president.

The unrest continued into the 2020 election cycle when a Ukrainian lawmaker described by US officials at the time as an “active Russian agent” released audio recordings of Democrat Joe Biden, then running for president.

That same year, Iranian hackers were blamed for emails purported to be from the far-right group The Proud Boys that officials said were designed to harm Trump’s candidacy.