Distributed denial-of-service (DDoS) attacks occur when an individual device, known as a bot, or a network of devices, known as a botnet, is infected with malware. These bots or botnets flood websites with increased traffic volumes over a period of hours or even days in an attempt to take services offline. Recently, hacktivist groups have begun leveraging DDoS attacks to extort site owners for financial, competitive advantage, or political reasons. This can represent a serious threat for enterprise businesses.
Planning and preparation are key to developing an effective DDoS defense. But first you need to understand how these attacks work.
DDoS Attack Types
New DDoS attack vectors emerge every day thanks to innovative artificial intelligence (AI) technology and a growing cybercrime ecosystem. But in general, there are three main types of DDoS attacks, each of which encompasses a variety of cyberattacks. The first is known as a volumetric attack, which primarily focuses on bandwidth and is designed to overwhelm the network layer with traffic. For example, domain name server (DNS) amplification attacks leverage open DNS servers to flood a target with DNS response traffic.
Another type of DDoS is a protocol attack, which exploits weaknesses in Layers 3 and 4 of the protocol stack, targeting critical resources. For example, synchronization packet floods (SYN) will consume all available server resources as a way to make servers unavailable.
Finally, a resource layer attack disrupts data transmission between hosts by targeting web application packets. For example, SQL injection attacks will insert malicious code into strings. These strings are subsequently passed to a SQL server to be parsed and executed.
And while these categories can cover a broad range of DDoS attacks, security teams also need to be aware that cybercriminals can compromise their networks by using multiple attack types from different categories.
Protecting Against, Responding to DDoS Attacks
When websites or servers go down, companies risk losing sales and customers, incurring high recovery costs and damaging their reputations. In some regions and industry sectors, they may even be subject to penalties and fines. Here are four ways to respond to DDoS attacks.
1. Evaluate Your Risks and Make Sure You’re Protected
The first step is to identify the publicly exposed applications within your organization. Make sure you note typical application behavior patterns so you can identify anomalies and respond accordingly. Because DDoS attacks typically spike during peak business seasons, such as the holidays, organizations should look for scalable DDoS protection services with advanced mitigation capabilities. Specific service features include traffic monitoring; adaptive real-time tuning; DDoS protection telemetry, monitoring, and alerting; and access to a rapid response team.
2. Get Prepared With a DDoS Response Strategy
One proactive measure that all companies should take is to develop a rapid response strategy. Start by forming a DDoS rapid response team that knows how to identify, mitigate, and monitor attacks. This team should also be able to work with internal stakeholders and customers.
3. Identify Potential Weaknesses
Use attack simulations to understand how your services will respond in the event of an attack. These simulations should confirm that your services or applications will be able to function normally without disrupting users’ experiences, and they should happen during off-business hours or within a staging environment to minimize business impact. When conducting an attack simulation, make sure you identify potential technology and process gaps to inform your DDoS response strategy.
4. Respond, Learn, Adapt In the Face of Attacks
In the event of an actual DDoS attack, contact an established DDoS response team or other technical professionals to conduct your attack investigation and post-attack analysis. This retrospective analysis is especially critical as it can help to clarify whether service or user disruptions were due to a lack of scalable architecture. Focus your evaluation on which applications or services experienced the greatest disruptions, as well as the effectiveness of your DDoS response strategy.
Of course, DDoS attacks are just one type of emerging cyberthreat. For more information on ongoing cybersecurity developments and best practices, check out Microsoft Security Insider.