Dec. 4 (UPI) -- Hackers attacked the House Republicans' chief fundraising committee before the midterm elections, stealing top officials' emails, a spokesman said Tuesday.
National Republican Congressional Committee spokesman Ian Prior said Tuesday a "cyber intrusion" by an "unknown entity" exposed sensitive emails.
Party officials said four senior NRCC aides had their email accounts hacked for several months, Politico first reported. An NRCC vendor discovered the breach in April and alerted the committee and a cybersecurity contractor. Still, senior House Republicans including Speaker Paul Ryan, R-Wis., House Majority Leader Kevin McCarthy, R-Calif., Majority Whip Steve Scalise, R-La., and other House Republicans were not made aware of the breach until Politico contacted them Monday.
A senior party official told Politico committee officials withheld information out of fear that revealing the attack could compromise efforts to find the hacker.
The NRCC hired Covington and Burling as legal counsel to respond to the hack. The law firm was paid over $150,000 for consulting from July to September, according to Federal Election Commission records.
The Democratic Congressional Campaign Committee raised more money than the NRCC in the 2018 election cycle, bring in $250 million compared to the NRCC's $174 million, data from the nonpartisan Center for Responsive Politics show.
Democrats ended up gaining a majority in the U.S. House of Representatives in the November elections while Republicans expanded their Senate majority by two seats.
An internal investigation and FBI investigation are ongoing.
The Democratic National Committee was hacked in the 2016 election cycle by Russian operatives, according to U.S. intelligence agencies. The hacked emails were published by WikiLeaks.
Special counsel Robert Mueller is investigating the hacked emails in his probe into alleged election interference.