BREAKING: Major U.S. Cities Under Terrorist Attack... This Is The Beginning Of The End Yesterday afternoon, Twitter experienced renewed outages following hours of internet disruption that took now several sites earlier in the morning across the East Coast. Shortly thereafter, a wave of reports of problems accessing many popular websites came in. As it turns out, the servers at a major Internet management firm had been hit by a severe cyberattack. New Hampshire-based Dyn claims its sever infrastructure suffered a distributed denial-of-service (DDoS) attack, which occurs when a system is overwhelmed by malicious traffic. The attack looks sophisticated, and is being investigated by the FBI. It doesnt look like a kid in a basement with a laptop, said CBS News homeland security correspondent Frances Townsend. It looks more sophisticated. A second attack around noon even impacted the FBI, and in the late afternoon Dyn warned that a third attack has just been resolved. Dyn told reporters at CNBS the attacks are well planned and executed, coming from tens of millions IP addresses at same time. The U.S. Department of Homeland Security also acknowledged the attack, assuring the public they are investigating all potential causes. The scale of the attack led to suspicions that it might be state sponsored, but ZDNet security editor Zack Whittaker claimed. It may or may not have been sponsored by some state-sponsored actor, at this point its simply too early to tell, he told CBS News. Security experts have expressed growing concern over denial-of-service attacks. Someone is extensively testing the core defensive capabilities of the companies that provide critical internet services, security expert Bruce Schneier told reporters. 