Martyn Williams (pictured) reported to PC Advisor on Wednesday that "A distributed denial-of-service attack aimed at AT&T's DNS servers has disrupted data traffic for some of the company's customers .. The multi-hour attack began Wednesday morning West Coast time and at the time of this writing, eight hours later, does not appear to have been mitigated .. The attack appears to have affected enterprise customers using AT&T's managed services DNS product".
AT&T said to the press on Thursday that the DNS issues have been resolved.
See also "US ISPs Agreed to Combat Major Cyber Security Threats" - here.
See "AT&T hit by DDoS attack, suffers DNS outage" - here.