Ex-DHS official says USIS breach likely affected other federal workers beyond Homeland agency

A former senior Department of Homeland Security official says the hacking incident that compromised the private files of more than 25,000 DHS workers also exposed data belonging to numerous workers at other federal agencies.

Christopher Cummiskey, who recently left his post as acting undersecretary for management at DHS, said Thursday the government was still identifying the precise numbers of those affected. He added that it could represent thousands more employees. Cummiskey also said officials found similarities in techniques used by intruders in the incident at U.S. Investigations Services LLC and an earlier breach at the Office of Personnel Management later linked to Chinese hackers.

Cummiskey spoke at a cybersecurity forum at the Center for National Policy think tank in Washington.

A USIS Investigations spokeswoman declined to comment.