According to the company, its engineers quickly took care of the issue, although some users continue reporting issues with access to web and email services:
Network Solutions experienced a distributed denial of service attack Monday afternoon, June 20, 2011 and again on Tuesday morning, June 21, 2011. Our engineers worked quickly to mitigate the attacks and services are in the process of being restored. We continue to monitor this situation, as potential risk still exists for these attacks to recur.
Last week, a DDoS extortionist got arrested for renting a botnet and attempting to blackmail German betting sites during the World Cup.