According to multiple reports, a group of hackers known as Lulz Security said on Twitter that it had breached the Senate's website.
The group said in a release that they would release a "small" amount of data from the Senate's homepage "in an attempt to help them fix their issues." According to The New York Times, the files that were released were mostly harmless.
A Senate spokesperson told the Times that security staff became aware of the attacks over the weekend, but that the hackers were not able to break through the government's firewall.
The group also took credit for hacking the servers of Bethesda Softworks, and that is has more than 200,000 user names and passwords from the gaming company's website.