Comey didn't specify the types of cyber assaults but said the planning appeared to be in its infancy. The director also noted that attacks of this nature are common among extremist groups that have trouble establishing themselves in the U.S.
“We are picking up signs of increasing interest,” Comey said. “It's a small but potentially growing problem.”
Despite efforts to implement stronger security measures, U.S. officials believe cyber gangs and state-sponsored hackers may pose a risk to critical infrastructure, according to the Wall Street Journal.
Comey also acknowledged that the U.S. knows exactly who is responsible for attacks against the Office of Personnel Management but declined to share the information.