FireEye's CEO also said it's difficult to know whether a mysterious postcard was in fact sent by a Russian intelligence agency.

Demers' position is one of the most powerful cyber-related perches in the U.S. government.

Reality Winner was found guilty of leaking classified government material.

The two world leaders are scheduled to meet on Wednesday amid a spate of ransomware attacks.

DOJ worked with international law enforcement to take down an online marketplace, Slilpp, offering stolen login credentials.

Manufacturing was its most targeted industry.