The agency reported that the compromised server is not part of the FBI’s internal mail system.
The FBI said on Sunday that hackers who hacked the bureau’s server a day earlier and sent out thousands of fake emails did not gain access to data or personal information on the departmental network.
The agency reported that it had eliminated the vulnerability in the software that made the attack possible.
Fake emails were sent from an FBI server designed to send notifications to a law enforcement portal that the FBI uses to communicate with state and municipal agencies.
The compromised server is not part of the FBI’s internal mail system, the agency noted.
A real address ending in @ ic.fbi.gov was indicated as the sender of fake emails warning of a possible cyberattack, the FBI said.