A massive, three-part cyberattack on Oct. 21 crippled some of the biggest, most popular websites.
The three cyberattacks were aimed at Internet traffic company Dyn, shutting down websites and services across the East Coast of the U.S.
“[The attacks were] well planned and executed, coming from tens of millions of IP addresses at the same time,” Dyn told CNBC.
The hack was a Distributed Denial of Service attack, which intentionally overwhelms a web service with traffic from many sources.
It is unknown who was behind the attack.
According to a senior U.S. intelligence official, the case is considered as internet vandalism, and does not appear to be a state-sponsored or direct attack.
The Department of Homeland security is “looking into all potential causes” of the attack. North Korea has been ruled out as a suspect, according to one U.S. intelligence official.
WikiLeaks supporter groups Anonymous and New World Hackers claimed credit for the attacks, stating it was retaliation for the Ecuadorian government’s decision to cut off WikiLeaks founder Julian Assange’s Internet connection after the site leaked internal documents from Democratic presidential candidate Hillary Clinton’s campaign.
“The specific target is anything big,” a spokesperson for New World Hackers said using the alias Prophet to POLITICO. “We were testing our power at first.”
Digital security researchers and U.S. officials are cautious in accepting the two groups are behind the attacks considering there is little evidence to support the claim. The groups have also reportedly taken credit in the past for high-profile attacks they did not perform.
Dyn said one of the sources of the attacks came from devices known as the “Internet of Things,” which includes DVRs, printers, cameras and appliances that are connected to the Internet, according to CNBC. The attacks used devices that were infected with a malware code recently released on the web.
"What they're actually doing is moving around the world with each attack," Dyn chief strategy officer Kyle York said on Oct. 21.
The attacks also impacted Dyn’s DNS advanced services monitoring for customers.
The second attack affected the West Coast of the U.S. and Europe, according to emails received from Gizmodo readers.
As of late in the afternoon, Dyn said the third cyberattack was resolved.
Affected websites include Twitter, Spotify, Reddit, Amazon, Business Insider, CNN, Etsy, HBO Now, Imgur, PayPal, Pinterest, Wired, Yelp, Fox News, The New York Times, BBC, Blue Host, Vox and Netflix.