Neustar's DDoS Attacks in the United Kingdom Survey [PDF file] of 381 UK-based IT professionals found that 22 percent of U.K. companies were hit by disruptive attacks in 2012, and 37 percent said those attacks lasted more than 24 hours.

Rates of attack varied widely by sector -- fully 53 percent of telecom companies, 50 percent of e-commerce companies and 43 percent of online retailers experienced DDoS attacks, while only 17 percent of financial firms in the U.K. were hit by such attacks.

Similarly, the financial impact of DDoS attacks varies by industry -- the financial services and telecommunications industries suffered the most damage from such attacks, with companies in the financial sector saying 26 percent of such attacks have a revenue impact of more than £100,001.

"DDoS attacks will continue to be part of the modern threat landscape because they are easy and relatively low-cost to perpetrate," Neustar senior vice president of enterprise services Alex Berry said in a statement. "They continue to be a threat to both large and small firms in all industries. Some of the recent large attacks have opened doors for even more malicious attackers to adopt similar tactics and Neustar fully expects to see the impacts of these attacks grow in line with their increasing complexity."