More than two dozen Congressional websites have been defaced by the Red Eye Crew, a group known for its regular attacks on websites.

The sites, some of which were using the Joomla content management system (CMS), were wiped of their regular content and replaced with a message coarsely expressing disapproval for US President Barack Obama.

Democrats seemed to be predominantly targeted. The attacks came around the same time as Obama gave his first State of the Union address on Wednesday night.

The Red Eye Crew has defaced thousands of websites, and some of the attacks have been recorded by Zone-H, a website that keep tracks of defacements, according to the blog of the Praetorian Security Group. The latest attacks had not been listed by Zone-H yet.

The hacked sites that Praetorian investigated were hosted on a server called "dcserver1.house.gov," but not all sites on that server were hacked. Many of the sites were using Joomla, which "might indicate that it is a Joomla component that is to blame, however that is just speculation," Praetorian noted. Joomla isn't the only CMS used by Congressional members, however, they wrote.

"Only the person who has access to the server the sites are running on and performs the analysis will be able to tell exactly what happened," Praetorian wrote.