The House of Representatives has banned staffers from accessing YahooMail until further notice, Gizmodo says.
Gizmodo's report on Tuesday was based on an email the House's Technology Service Desk sent to staffers in April. The email, which the site obtained, said the House had noticed a rise in ransomware — attacks in which hackers attach malicious software to emails — entering staffers' inboxes, particularly through YahooMail.
"The House Information Security Office is taking a number of steps to address this specific attack," the email said.
"As part of that effort, we will be blocking access to YahooMail on the House Network until further notice."
Yahoo told Gizmodo it is working with the House's information technology team to improve users' security.
For more on the ban, read Gizmodo's report.
Disclosure: CNBC has a content-sharing partnership with Yahoo's finance site.