Officials confirmed Wednesday that the Library of Congress fended off what it called a “massive and sophisticated DNS assault” that resulted in the disruption of services and websites. The distributed denial of service (DDoS) network attack employed multiple forms of attack, “adapting and changing on the fly.”

Affected services and websites include Congress.gov, the U.S. Copyright Office, the BARD service from the National Library Service for the Blind and Physically Handicapped, many databases, and both incoming and outgoing email.

A team of team of Library IT professionals and contract partners returned networked services to normal functionality, “while maintaining the security of the Library’s network,” said Bernard Barton, chief information officer of the Library of Congress.

“We’re satisfied that we’ve fended off the attack and fortified our system for now, but we’ll continue to be vigilant and employ state-of-the-art security systems to effectively respond to these type of incidents in the future,” said Barton.

“This is not the first time that a large agency or organization has been targeted with this kind of denial of service, and it certainly won’t be the last,” he added.

Library officials say they have turned over key evidence to the appropriate authorities, who will investigate, and “hopefully bring the instigators of this assault to justice.”