Cyberwar keeps CIA's Brennan up at night

CIA Director John Brennan said he believes it is inevitable that the Islamic State group will try to stage an attack on American soil, and the growing threat of cyberwarfare "really is the thing that keeps me up at night."

"The cyber environment can pose a very, very serious and significant attack vector for our adversaries if they want to take down our infrastructure, if they want to create havoc in transportation systems, if they want to do great damage to our financial networks," he said in a Feb. 14 interview on CBS' "60 Minutes."

At the same time, Brennan does not appear to forecast an imminent widespread cyberthreat from terrorists or other non-state actors.

"Having the capability [to attack the grid and other critical infrastructure] but then also having the intent are two different things," he said. "I think fortunately right now those who may have the capability do not have the intent. Those who may have the intent right now I believe do not have the capability [because] if they had the capability, they would deploy and employ those tools."

Brennan knows firsthand the capabilities of cyber malefactors. In October 2015, his personal email account was hacked by a teenager posing as a Verizon employee.

The incident "shows that there are ways that individuals can get into the personal emails of anybody," he said.

In February 2015, Brennan announced a plan to ramp up the CIA's focus on increasing national security and intelligence in the face of mounting cyberthreats.

When asked what he learned from the terrorist attacks in Paris last November, Brennan said, "There is a lot that [Islamic State] probably has underway that we don't have obviously full insight into. We knew the system was blinking red. We knew just in the days before that [Islamic State] was trying to carry out something."

Brennan didn't precisely say the Paris attackers used encrypted apps to communicate, but he did tell CBS correspondent Scott Pelley that "the individuals involved have been able to take advantage of the newly available means of communication...that are walled off from law enforcement officials."

In the wake of the Paris attacks, Brennan said he told the CIA "we have to work harder. We need to have the capabilities, the technical capabilities, the human sources. We need to be able to have advanced notice about this so that we can take...the steps to stop them."