A sudden increase in ransomware attacks prompted the U.S. Congressional IT department to ban access to both applications on Google-hosted apps and Yahoo Mail until further notice.
An email from the House technology service desk said the "primary focus" of the recent attacks "appears to be through Yahoo Mail," according to the International Business Times.
Several other apps—including appspot.com, where Google hosts custom-built apps—were also blocked, pending further investigation into the incidents.
An e-mail sent April 30 from the House technology service desk obtained by Gizmodo and TechCrunch reads, "In the past 48 hours, the House Information Security Office has seen an increase of attacks on the House Network using third party, web-based mail applications such as Yahoo Mail, Gmail, etc. The attacks are focused on putting 'ransomware' on users' computers."
As a result of the department's concerned they moved to ban Yahoo Mail on the House network "until further notice." On May 3, the department also blocked appspot.com over fear that it was still hosting a remote access trojan.
A report issued by Kaspersky Lab last week found ransomware is now the most prolific cyberthreat of 2016. And while private industry stands to lose huge amounts of money in such attacks, an attack on the government could potentially expose a trove of confidential information.
A spokesperson for the House Chief Administrative Officer declined to confirm whether or not any of the recent ransomware attacks were successful, according to TechCrunch.
FBI cyber division assistant director James Trainor recently advised companies that become victims of a ransomware attack not to pay because it only encourages the hackers.