US Congress 'bans members' Yahoo Mail' Published duration 12 May 2016

image copyright Thinkstock image caption Both Yahoo and Google said they were working with Congress to resolve the issue.

A series of ransomware attacks on the House of Representatives has led US Congress to ban members from using Yahoo Mail, according to a leaked email.

Both Yahoo Mail and Gmail are named in the 30 April email, published on Thursday by Gizmodo , saying the attacks had increased "in the past 48 hours".

Yahoo Mail will be blocked "until further notice" it adds.

Ransomware encrypts victims' files and demands a ransom be paid for unlocking.

Meanwhile, an unnamed House of Representatives employee has told Reuters devices connected to the internet via its wi-fi or ethernet cables have been barred from accessing appspot.com, the domain where Google hosts custom-built apps.

"We began blocking appspot.com on 3 May 3 in response to indicators that appspot.com was potentially still hosting a remote access Trojan named BLT that has been there since June 2015," the news agency was told.

Reuters' sources said the FBI had originally warned Congress of the potential vulnerabilities.

Former House of Representatives employee Ted Henderson told Reuters two Google-hosted apps he had created to allow members of Congress to discuss politics and share notifications about votes had been hit by the ban.

Both Yahoo and Google said they were working with Congress to resolve the issue.