NEW YORK, Oct 27 : The US Federal Election Commission's website has been targeted by a hacker or hackers, according to an email seen by Reuters, disrupting the agency's electronic filings system a week before the November 3 elections.

The cyberattack comes as so-called super PACs and dark money groups spend record sums in the final days of the races. The elections will determine whether President Donald Trump's Republicans maintain their majorities in Congress for the next two years.

In a statement, the FEC said, "at this time, the FEC’s electronic filing system is currently offline and our IT staff are actively working to restore service." The FEC, which tracks the spending of candidates and political committees, said users could still search the website for past reports. It declined further comment on the outage.

The FEC does not play a role in administering US elections and the outage should have no effect on voters' ability to cast ballots.

The outage prevents organizations from filing the FEC's 24-hour and 48-hour spending reports, which show how much political groups and others are spending on specific races.

"I've never seen this in 26 years," said Steven Mele, president and CEO at political finance compliance firm MBA Consulting Group. "The result is there will be less disclosure on the elections" until it's fixed.

A status message posted by the FEC said its filing system had been down since around 10 p.m. ET on Monday (0200 GMT Tuesday). The Cybersecurity and Infrastructure Security Agency referred questions to the FEC. The FBI did not immediately return messages seeking comment.

The FEC posted the notice after campaign finance officers couldn't file mandatory reports late on Monday.

"We have a bad actor attempting to breach FEC systems. As a result, we’ve had to temporarily shut down our web facing services," an FEC electronic filings officer said in the email to several campaign compliance firms that night.

The midterms are now the most expensive US election in history with roughly $11.21 billion spent on advertising and future reservations so far, according to political ad tracker AdImpact. It's surpassed the previous record set in the 2024 elections when $11.2 billion was spent on all races, including $3.2 billion on the presidential race between Trump and former Vice President Kamala Harris, AdImpact said.

Much of the spending is being driven by super PACs, which can accept unlimited amounts of money from wealthy individuals and corporations and spend as much as they want on campaigns with few restrictions.

The sums being spent in recent weeks are staggering as Democrats gain ground in several Republican strongholds.

Super PACs and dark money groups have spent an average of over $50 million per day over the last week, said Brendan Glavin, research director at nonpartisan campaign watchdog group OpenSecrets. More than $250 million in spending was reported on October 20 alone, he added.

"It's a big deal," he said of the outage, which leaves voters in the dark until the filing system is back online.

"These are the key reports that tell us what is happening," Glavin said. "In the last days of the election this is the only way for us to keep track of where the money's being spent" and who's spending it.