"The Department of Homeland Security and other federal agencies are here to help. We seek to raise the level of cybersecurity in both the private sector and civilian government, and provide timely information to protect all our systems against cyber threats," he said in a statement.

Johnson urged companies to adopt the voluntary Cybersecurity Framework of best practices to protect against cyber risks.

(Reporting by Doina Chiacu; Editing by Alden Bentley)