Access to Congress.gov was interrupted intermittently beginning around 9 p.m. ET Thursday until the website was restored to normal operation “just after” 11 p.m. ET, said April Slayton, director of communications from the Library of Congress, which runs the website, to CNN.
“The Library of Congress used existing measures to respond quickly to the attack, resulting in minimal downtime,” Slayton said in an email. “The library’s network was not compromised and no data was lost as a result of the attack.”
A Russian-speaking hacking group known as Killnet claimed responsibility for the hack on its Telegram channel. The post included a screenshot of an error message on Congress.gov overlaid with an image of President Joe Biden with a puzzled look on his face.
The hackers used a popular tactic known as a distributed denial of service (DDoS) attack, according to Slayton, which floods computer servers with fake web traffic in an attempt to take websites offline. Congress.gov displays information about congressional bills, hearings, and other proceedings.
While DDoS attacks can have hardware consequences, such as when customers can’t access banking websites, sometimes they’re more about making a statement and getting noticed.
Ahead of Russia’s full-scale invasion of Ukraine in February, the White House blamed Russian military intelligence for a series of DDoS attacks on Ukrainian government websites.
US officials have been on high alert for months for retaliatory Russian cyberattacks after the Biden administration imposed tough sanctions on Russia for its invasion of Ukraine. But there have been no reports of high-impact hacks on US organizations linked to Russian government agents.