Twitter, Netflix, other websites knocked out by major cyber attack

Several websites including Twitter, Amazon, Netflix, and Spotify were inaccessible by many users in the United States (and other parts of the world) on Friday.

The websites were unreachable due to a Distributed Denial of Service (DDoS) attack.

DDoS is when a web service is intentionally overwhelmed by traffic from many sources. It is a common method for digital assaults.

According to The Wall Street Journal, web-technology provider Dynamic Network Services Inc., known as Dyn, said its domain name system or DNS service was subject to a massive distributed denial-of-service attack from 7:10 a.m. on Friday.

Dyn reported a second attack by noon after the first attack was resolved.

The Department of Homeland Security told CNBC that it is “looking into all potential causes” of the attack. NBC News reported that one U.S. intelligence official said North Korea had been ruled out as a suspect.

NBC News reported that one U.S. intelligence official said North Korea had been ruled out as a suspect.

The White House said U.S. authorities are monitoring reports of the attack on the internet services company and whether it is a “criminal act,” according to Reuters.

“The internet continues to rely on protocols and infrastructure designed before cyber security was an issue,” said Ben Johnson, a former engineer at the National Security Agency and founder of the cyber-security company Carbon Black.

“We’re still digging into the root cause, but ultimately it was limited to the East Coast of the U.S.,” Dyn spokesman Adam Coughlin said.