About 32% of companies estimate that DDoS outage has cost their companies over £240,000 per day losses.
According to a survey by Neustar, a majority of UK businesses are not properly equipped to prevent DDoS attacks even though 91% of them see it as big threat.
The survey found that about 32% of companies estimate that DDoS outage has cost their companies over £240,000 per day.
There is also a 200% spike in attacks affecting bandwidth between 1-20 Gbps, and a significant increase in attacks on bandwidth with a magnitude of 100 Gbps or more.
During last year there was over a 35% increase in the number companies hit by DDoS attack over 2012, while the length of attacks has increased during the year with 28% of the attacks lasting up to two days.
Adding to the worries of the companies, there is a 69% percent chance of a repeat attack after the first attack.
More than 40% of the attacked companies among those surveyed said that they lost funds, data or intellectual property.
About 31% of these companies were DDoS-attacked just once, over 48% were targeted two to 10 times.
DDoS attacks that required more than six people to address have increased 56% during the year from 25% in 2012 to 39% during last year, while DDoS attacks requiring more than 10 people to mitigate has doubled from 12% to 24% during the year.
About 96% of the businesses said customer support is the biggest fall out of the DDoS attack, about 89% say brand or customer confidence, while 82% say revenue loss is biggest impact, and 55% say theft is the biggest impact.
Neustar senior vice president and technology fellow Rodney Joffe said organisations must remain constantly vigilant and abreast of the latest threats.
"Even with proper mitigations in place, the attack caused an upstream ripple. It is a constantly changing threat landscape," Joffe added.
The survey found that there is an increase in DDoS "smokescreening" attacks in which the cyber criminals grab and clone private data to siphon off funds, intellectual property while IT and security teams are fully distracted by a DDoS attack.
Joffe added, "When there is a tremendous storm, you run around your house making sure all windows are closed and you have got the flashlights ready. You are not worried about anything else."
"DDoS attacks are similar. They create all-hands-on-deck mentality, which is understandable but sometimes dangerous."
The report was prepared based on survey of 331 companies including financial services, technology, retail, government/public sector, health care, energy/utility, telecommunications, e-commerce, Internet services and media.