Knowns and unknowns about the hack at Colonial Pipeline

Cybersecurity FireEye is involved with the incident response, according to three industry sources. [Reuters.]

Ransom-seeking hackers have broken into Colonial Pipeline, prompting the company to shut one of America's major arteries for fuel delivery.

Here is a look at what we know, and what we don't, about one of the most disruptive digital shakedown efforts to hit a U.S. company.