(Reuters) – Hackers obtained the personnel documents from certain police departments in Washington DC in a ransomware attack that was revealed on Monday, CNN quoted the department's acting police chief as saying late on Thursday.
"HR-related files with personally identifiable information were obtained," Robert Contee wrote in an email to staff, according to CNN.
The US media on Monday reported that the police department has engaged the FBI after its server was hacked, with a Russian-language ransomware group called Babuk claiming responsibility.
Ransomware groups hold files and networks hostage unless a payment is made. The US State Department has said dealing with such groups is a top priority.
"As we continue to determine the magnitude and extent of this intrusion, please note that the mechanism allowing unauthorized access was blocked," Mr. Contee wrote, adding that the department "worked to identify all affected staff."
The police department did not immediately respond to Reuters' request for comment.