Eli Blumenthal and Elizabeth Weise write that Amazon, Twitter, Spotify, Netflix and PayPal were among the websites hobbled by the DDoS attack on the Dyn service Friday.
The report said security experts believe the source of attack came from internet-connected devices infected with the Mirai malicious source code.
Mirai uses malware from phishing emails to infect computer or home networks initially, then spread the virus to various devices to create a robot network, Blumenthal and Weise noted.
CNBC reported Friday the Department of Homeland Security examines the potential causes of the Dyn attack and that a U.S. intelligence official does not think the incident was a state-sponsored or a directed attack.
A team of Dyn engineers worked to restore the company’s service shortly after they discovered the cybersecurity incident, according to CNBC.