The Library of Congress said hackers broke into its communications systems and were able to read its email correspondence with congressional offices for most of this year.
In a private notification sent Friday to some congressional offices, obtained by NBC News, the Library of Congress said that hackers “accessed email communications between congressional offices and some Library staff, including the Congressional Research Service.” The hackers had access from January until September, the notification said.
The Library of Congress, the world’s largest library, offers a dedicated research staff for Congress. Last year, it gave congressional staffers more than 76,000 custom responses to inquiries, according to its most recent annual report.
Bill Ryan, director of communications at the Library of Congress, told NBC News in an email that the software vulnerability the hackers used to gain access has been “mitigated.”
“The Library has referred the matter to law enforcement and is also conducting its own analysis of the breach,” Ryan said.
The notice did not cite who was behind the hack, only referring to the hackers as “the adversary,” a term sometimes used in the cybersecurity industry.
Countries with strong cyber espionage operations, including the United States, routinely try to target adversarial countries’ government networks and legislators’ communications in order to gather intelligence. In recent years, China and Russia, both of which have strong cyber espionage agencies, have conducted sophisticated hacking operations to spy on the US government.
Four years ago, the US accused Russian cyber spies of hacking a commonly used software made by a company called SolarWinds, giving those hackers access to multiple US agencies, as well as hundreds of private companies. The Russian Embassy in Washington, DC, previously called the attribution “groundless.”
The US has also accused China of multiple cyber espionage operations against the country, most recently one that hacked into several American telecommunications companies to spy on both parties’ recent presidential campaignsas well as the staff of outgoing Senate Majority Leader Chuck Schumer, DN.Y. A spokesman for the Chinese Embassy previously declined to comment.