IRVING, Texas, June 30, 2014 /PRNewswire/ -- Disruptive cyber-attacks are becoming more effective at breaching security defenses, causing major disruption and sometimes bringing down organizations for whole working days, according to a new global study from BT. The research reveals that 41 percent of organizations globally were hit by Distributed Denial of Service (DDoS) attacks over the past year, with three quarters of those (78 percent) targeted twice or more in the year. DDoS attacks are seen as a key concern by more than three-quarters of US organizations (78 percent). This is higher even than the global average (58 percent). The new study explores attitudes to and preparedness for DDoS attacks of IT managers from organizations in eleven countries and regions around the world. It reveals that while most US organizations (72 percent) have a response plan in place should a DDoS attack occur, only a quarter are convinced that they have sufficient resources in place to counteract an attack (26 percent). DDoS attacks can cause major disruption for organizations; they can take down an organization's website, overwhelm a datacenter or generally cause networks to grind to a halt and become unusable. They are also increasingly becoming more complex and difficult for organizations to fend off. Almost six in ten (59 percent) of those polled agree that DDoS attacks are becoming more effective at subverting their organization's IT security measures. Attackers are often adopting hybrid, or multi-vector, attack tactics which involve attacks through multiple platforms. These have increased by two-fifths (41 percent) during the past year. Multi-vector attacks pose increased complexity and risk as they involve multiple attack methods deployed simultaneously. These often require a dedicated mitigation team to track and combat the threat across multiple fronts, as automated systems are less likely to be able to offer adequate protection.