A series of cyberattacks brought down websites across the United States on Friday as hackers attacked networks operated by Dyn.

A wide range of websites, including those belonging to Twitter (TWTR) - Get Report , the New York Times (NYT) - Get Report , Amazon.com (AMZN) - Get Report , Starbucks (SBUX) - Get Report and Yelp (YELP) - Get Report , were affected, mainly along the East Coast beginning this morning. A third wave of attacks began just after 4 p.m. Eastern time.

Dyn, a domain name system services company, confirmed on Twitter that it was grappling with distributed denial-of-service (DDoS) attacks. A DDoS attack floods the affected service with traffic, overloading the server and preventing new connections.

Dyn described the attacks to CNBC as "well planned and executed, coming from tens of millions of IP addresses at the same time."

While DDoS attacks don't steal data from affected websites, Dyn's struggles come amid renewed focus on cyberattacks and cybersecurity. WikiLeaks has published the hacked emails of the Democratic National Committee and Hillary Clinton campaign chairman John Podesta. James R. Clapper Jr., the director of national intelligence, and the Department of Homeland Security have blamed the leaks on Russian officials, and private security companies have also blamed WikiLeaks.

WikiLeaks founder Julian Assange, a noted Clinton critic, has been holed up in the Ecuadorian embassy in London since 2012 to avoid an outstanding rape charge in Sweden. The Ecuadorian government shut down Assange's access to the Internet in response to the leaks, saying in a statement that it "respects the principles of nonintervention in the affairs of other nations, does not meddle in electoral campaigns nor support any candidate in particular."

"Mr. Assange is still alive and WikiLeaks is still publishing," WikiLeaks tweeted shortly after 5 p.m. "We ask supporters to stop taking down the US internet. You proved your point."

Privately held Dyn announced May 10 that it had secured a $50 million Series B investment from private equity firm Pamplona Capital Management.

Action Alerts PLUS, which Cramer co-manages as a charitable trust, is long SBUX.