Maintaining website security has become such a tremendously intricate process as technology seems to be forever evolving. The general perception is that you can protect your online business against current threats through analysis of past attacks, but remain clueless about security loopholes that might come into play as the Internet continues to develop and technology incessantly evolves. It’s like a vicious cycle where attackers and defenders skirmish to get the upper hand – each time a security breach is countered by expensive security measures, attackers dig up new vulnerabilities and/or enhance their tools to sidestep newly developed security systems. Hence, web hosting security tools that are applicable today may not hold ground the following year. A particular website vulnerability that doesn’t look like it would disappear anytime soon is the DoS attack and its variation – DDoS attack. Denial-of-service (DoS) Attack Simply put, denial-of-service (DoS) attack is an attempt to make computer resources unavailable to its intended users and prevent legitimate users from accessing information or services. Although motives, targets, and modes and methods of carrying out this malicious attack may vary, its general intention is to thwart a website from functioning efficiently, if at all – either temporarily or for an indefinite period. A typical and most obvious form of DoS attack happens when an attacker floods (overloads) a particular network/server with external communication requests or information so that the victim could not respond (or respond so excruciatingly slow) to legitimate traffic. DoS attacks either force the target computer to reset or saturate its resources that it can no longer provide the intended service; blocking the communication media and rendering the site inaccessible to legitimate users. Distributed Denial-of-service (DDoS) Attack A DoS attack involves a single attacker that attacks the target system. In DDoS attacks, however, multi-level attackers are involved, which makes it harder to counter and are consequently more dangerous. An attacker could take control and use other computers (including yours) to attack the target system. DDoS attacks have been known to topple down whole corporations and, in some instances, even entire web hosting companies. The danger lies in that these attacks imitate genuine traffic habit, so it is very difficult to identify them until it’s too late and the damage is done. DDoS attack is thus called “distributed” because the attacker uses multiple computers to launch the denial-of-service attack. Is Your Website at Risk? You may have read or heard about denial of service attack launched against huge and sensitive websites but don’t think that target sites are limited to high-profile web servers such as banks, root name servers or credit card payment gateways. Unfortunately, anybody can get hit with a DDoS attack and your website is not immune to the risk. It could only take a powerful competitor that wants to bring you down to initiate such reprehensible actions – and that definitely makes your business vulnerable. Even more disquieting is the fact that these attacks occur on sites that are not even business-oriented. Attackers frequently use smaller sites that don’t have resilient security to practice their skills on. If your site is not adequately protected, then it is definitely at risk for DDoS attacks. Is There a Way to Identify a DDoS Attack? It is quite difficult to make a distinction between DDoS attacks and common network activity or service disruptions. There might be technical problems in a specific network or maintenance processes being performed by system administrators that may be misconstrued as denial-of-service attack. However, the following symptoms could be indicators that a DoS or DDoS attack is in progress: •           Radical increase in the amount of spam you get in your account. •           Inability to access any website. •           Abnormally sluggish performance of the network (i.e., accessing websites, opening files, etc.) •           Specific websites are constantly unavailable. How Do You Avoid a DDoS Attack? The sad fact is there are no simple solutions to take the edge off the threat of DDoS attacks; neither is there a foolproof prevention plan with effective ways to avoid becoming the victim of a DoS or DDoS attack. However, there are some steps and strategies that can help reduce the likelihood of attackers using your computer to launch a DDoS attack, as well as minimize the impact of a large-scale attack. •           Install and maintain adequate anti-virus software. •           A good technical solution is to put limits on the types of traffic you allow into your network. One way of addressing this is to install a firewall and configure it to restrict traffic coming into and leaving your computer. Upstream providers would also need to asses appropriate limits to traffic levels that may present problems at various points in the network. •           Stick to good security habits and practices when distributing your e-mail addresses. Applying e-mail filters is also a good way to manage unwanted traffic. •           Most crucial of all, use a web hosting service provider that has proven capability to foil DDoS attacks. You may be tempted to go for low priced plans with sloppy security measures; you could undermine and jeopardize your online business (especially if it is a thriving one). Remember that you stand to lose thousands of dollars with a single error; it is therefore vital that you choose the most qualified web hosting company. Source: DDoS Attacks: How Vulnerable Is Your Site to the Threat?