Since the onset of the pandemic, organizations have been relying on remote operations, teleworking and remote access infrastructure to keep operations running. However, this has opened doors for attackers to target the backend of the communication infrastructure of organizations to reduce productivity. There has been a surge in Distributed Denial of Service (DDoS) attacks as we enter 2021, including highly complex multi-vector attacks that are quite challenging to mitigate. The biggest attack over the past 15 months measured 500 Gbps and used no fewer than five different attack vectors. Seeing how a single DDoS attack can paralyze even the most well-structured network for days, costing a fortune in lost sales, freezing online services and crippling a company’s reputation, here are the most common types of DDoS attacks and how to stop them from bringing your company down.

The most Common Types of DDoS Attacks

In essence, a distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, making it unavailable for legitimate users.

Volumetric attacks

These types of DDoS attacks employ methods to generate massive volumes of traffic to overwhelm a server and clog up the available bandwidth resources to make it impossible for legitimate traffic to get through to the targeted site. Most common volume-based attacks include UDP floods, ICMP floods, and other spoofed-packet floods.  UDP flood targets random ports on a computer or network with UDP packets, while the ICMP attack floods the target with request packets, causing the target to respond with an equal number of reply packets.

Application-layer Attacks

Application-Level attacks exploit vulnerabilities in applications with known weaknesses, instead of attacking the server. The downside to application layer-attacks is that they are the hardest to detect. These attacks work by opening connections and initiating process and transaction requests that can deplete valuable resources such as bandwidth and available memory. for instance, under an HTTP flood attack, the attacker mimics a seemingly normal interaction with a web server or application, but the interactions are designed to eat up as many server resources as possible.

Protocol Attacks

These attacks are targeted further down the stack and focus servers, routers, firewalls, load-balancers, intrusion detection/ prevention system (IDS/IPS) devices, and other IT infrastructure. For instance, A SYN flood is when an attacker rapidly initiates a connection to a server without finalizing the connection, keeping the server waiting endlessly for half-opened connections.

How To Mitigate a DDoS Attack?

Have an Effective DDoS Mitigation Plan

First things first, companies should determine the applications and network services that can come under fire in the events of a DDoS attack, and draft an emergency response plan to mitigate those attacks. At a time when cybercriminals are getting smarter, and using a combination of different tactics to foil security teams, evade detection, and maximize results, organizations need to anticipate these attacks and plan their response accordingly. Increasingly, companies are seen integrating their internal applications and networking teams, and training their incident response team so that they are aren’t left unprepared. However, despite your best efforts, be prepared for the worst and have a disaster recovery plan in place, in case a business-disrupting attack does happen.

Secure Your Network Infrastructure

29 percent of DDoS attacks take place at the network layer, which makes it all the more important to protect your business against network security threats by implementing stolid multi-level protection strategies. This requires combining state-of-the art threat management systems with multi-layered DDoS defense techniques, such as content filtering, VPN, firewalls, load balancing, and proactive intrusion prevention, to prevent a Denial-of-Service attack from occurring in the first place. This includes everything from identifying anomalies in traffic to quarantining bad traffic. Backed by secure infrastructure, these systems are the only way of mitigating DDoS threats. You should also partner with reputable traffic scrubbing providers to combat and re-route attacks, using the Border Gateway Protocol (BGP) or the Domain Name System (DNS), before they reach your network infrastructure. In addition, you need to keep your systems updated, since outdated systems are plagued by security loopholes that make them highly vulnerable to DDoS attacks. To stop attackers in their tracks, you need to install the latest software versions and patch your network infrastructure with the latest security updates to close off all paths for attackers.

Stop Relying on Traditional On-Premises Security Devices 

On-perimeter defenses, such as firewalls, load balancers, and intrusion prevention systems, often fail to mitigate DDoS attacks. The reason is that these devices are vulnerable and your managed security service provider should divert these attacks before they reach those devices.

Sure, effective traffic monitoring tools will keep you abreast of any spikes in traffic, but how will you tell legitimate traffic from bad one? Not to mention, simply monitoring traffic won’t stop your network resources from getting overwhelmed? Traffic monitoring and setting threshold limits can be construed as more of a preventive measure than stand-alone protection, especially since threshold triggers mostly tend to overlook sub-saturating attacks. Similarly, you can’t just install a firewall or an intrusion prevention system and relax thinking that your business is immune from a DDoS attack. Most firewalls tout unparalleled anti-DDoS capabilities, but in reality, they only work on setting threshold limits. When the traffic crosses this limit, they block every user and application, causing your website to crash. Hackers have discovered this loophole and use it to oust even legitimate users from your website. Since website and network experiences a downtime anyway, the goal of a DDoS is achieved.

Multi-vector DDoS protection

Multi-vector attacks, that combine different techniques to get around current defenses and target a server, service or network, escape detection and are extremely hard to guard against. Instead of a single, large, one-off attack, hackers are preferring a mix of many amplifications and more traditional attacks that change in response to the cyber-defenses they encounter. The total attack rate will be the sum of all vectors. Even if your incident response team detects such an application-layer attack, the rate at which the parameters and vectors are automatically changed ensures that your average, run-of-the-mill DDoS protection solutions cannot engage mitigation fast enough to prevent downtime. The attackers usually hide in shadows and watch how sites respond to attacks, and as soon as the site goes back online, the hackers would adjust with new and more sophisticated attack methods. Such multi-vector attacks required multi-threaded approach, such as recognizing each and every vector and responding in real-time without affecting any legitimate traffic in turn.

Make The Infrastructure Architecture as Resilient as Possible

To prevent downtime in case of an attempted DDoS attack, companies should spread their data servers across multiple data centers to distribute traffic between them. This will make it harder for aggressors to launch a server level attack. Most companies distribute their data serves across different countries with a good load balancing capability or at least use different Internet service providers, so that offenders won’t be able to attack more than a portion of your servers, leaving the other unharmed. However, this strategy is only useful when all these remotely located servers are connected to different networks without any network bottlenecks, such as only using a single connection to the outside internet. A resilient network architecture goes a long way towards mitigating DDoS attacks without affecting traffic.

Be Prepared for Traffic Spikes

Overprovisioning or scaling up network bandwidth to much more than you ever think you are likely to need, helps to absorb unexpected traffic spikes and protect against volumetric DDoS attacks. However, the only downside to this mitigation strategy is that volumetric attacks may require an unusually large bandwidth, which small and medium businesses may not be able to afford. However, since the possibility of your business ever falling prey to a DDoS business is small, you need to partner with a service provider that helps you scale up on demand rather than pay an arm and a leg for redundant network interfaces and devices. That said, it can be hard to predict a DDoS attack and even the nature of the attack can change midstream. However, every attack somehow focuses on depleting your Internet bandwidth, which is why having more bandwidth available to your Web server can help to mitigate an attack head-on.

Deploy the right hardware

Using the right hardware helps you keep common types of DDoS attacks at bay. Tools such as network and web application firewalls and load balancers can mitigate most layer-4 attacks and application-layer attacks. In the event of SYN flood attacks, you can tweak the settings on most hardware devices to close TCP connections as soon as the threshold limit is reached. Not to mention, you can also configure the firewalls around routers to block DNS responses from outside your network and filter out nonessential protocols. you should also set lower SYN, ICMP, and UDP flood drop thresholds. While this cannot mitigate the attack completely, this makes sure that your business is protected from the worst of ping-based volumetric attacks and keep operations going. 

Install DDoS Protection Appliances

There are myriad DDoS protection appliances that sit in front of network firewalls and thwart all DDoS attacks in the bud even before they happen. These DDoS protection appliances work across the principle of traffic behavioral baselining and filtering out all bad traffic, as well as traffic that carries well-known attack signatures. However, these appliances are only as good as the traffic throughput they are capable of handling. Even the best DDoS protection appliances will fail to inspect and block traffic that is arriving over the rate of 80 Gbps, but unfortunately, attackers are getting more sophisticated in their attack strategies.

FAQs

What does DDoS Protection do?

DDoS mitigation refers to the utilization of various specially designed network equipment or a cloud-based services that protect a targeted server or network from a distributed denial-of-service (DDoS) attack.

What is the most common DDoS attack?

The most common DDoS method by far is the UDP flood – or the User Datagram Protocol. Under this type of attack, the attacker overwhelms random ports on the targeted host with IP packets containing UDP datagrams. In fact, Volumetric DDoS accounted for 73% of all incidents in the last quarter of 2020.

What is a Layer-7 Attack?

An application layer DDoS attack attempts to overwhelm network or server resources with a flood of traffic. This type of attack exploits loopholes, vulnerabilities, and/or business logic flaws in the application layer to bring the system down and block access to the website or service for normal users.

How much do DDoS attacks cost?

A single DDoS attack can set a small to medium business back by around $120K. In addition, large enterprises could expect a whopping loss of $2M for an attack.

What is the purpose of a DDoS Attack?

The sole purpose of a DDoS attack is to prevent legitimate users from accessing your website. However, DDoS attacks are also used for extortion and blackmailing. You may be asked to pay a ransom to stop the attack.