A DDoS attack is a cyberattack on a specific server or network with the intended purpose of crashing that network or server’s normal operation. This is done by flooding the targeted network or server with a constant flood of fake traffic such as fraudulent requests, which overwhelms the system. Excessive traffic overloads resources and disrupts connectivity, preventing the system from processing genuine user requests. Services become inaccessible, and the target company experiences delayed downtime, lost revenue, and disappointed customers.
 
While some hackers use DDoS attacks to blackmail a business into paying a ransom more common motives behind a DDoS are to:
  • Disrupt services or communications.
  • Inflict brand damage.
  • Gain a business advantage while a competitor organization’s website is down.
  • Distract the incident response team.
DDoS attacks can cause damage to businesses of all sizes. Statistically, DDoS hackers most often target:
  • Online retailers.
  • IT service providers.
  • Financial and fintech companies.
  • Government entities.
  • Online gaming and gambling companies.
A DDoS is an attack from numerous sources at the same time. The computer, which is the ringleader communicates with other computers around the world and co-ordinates an attack on a server. Instead of an attack coming from a single source, the server now has to deal with an attack from multiple sources and when this happens it overwhelms the server and eats up the network bandwidth. As a result, the legitimate computers are denied services because the server stays preoccupied with a DDoS attack.
Attackers typically develop a malware program, distribute it over the internet and put it on websites and email attachments. When a vulnerable computer visits these infected websites or emails, the malware gets installed on that computer without them having any knowledge and the infected computer then becomes a part of a group of other infected computers to perform a DDoS attack. This group of infected computers is called a botnet which could be hundreds or even thousands of computers that are scattered all over the world. The attacker who acts like a centralized command and control center for the botnet, then sends out commands to all these computers and asks to launch the attack at a certain date and time. Once the set time comes the attack begins. A DDoS can last for hours or even days and it depends on the attacker’s intent. 
According to Cisco, the total number of DDoS attacks will double from the 7.9 million in 2018 to over 15 million by 2023.
While a DDoS does not directly lead to a data breach, the victim spends time and money getting services back online. Loss of business, abandoned shopping carts, frustrated customers, and reputational hurt are usual outcomes of failing to prevent DDoS attacks. Hence it is important to be aware of the prevention techniques of this kind of attack.

Prevention:

1.    Create a DDoS Response Plan

A security team should develop an incident response plan that covers:
  • Clear instructions on how to react to a DDoS attack.
  • Steps to maintain business operations.
  • Go-to staff members and key stakeholders.
  • Escalation mechanisms.
  • Team responsibilities.
  • A checklist of all necessary tools.

2.    Ensure High Levels of Network Security

Safeguarding networking devices helps to prepare the hardware (routers, load balancersDomain Name Systems (DNS), etc.) for traffic spikes.
The following types of network security can help to protect business from DDoS attempts:
  • Firewalls and intrusion detection systems acting as traffic-scanning barriers between networks.
  • Anti-virus and anti-malware software detecting and removing viruses and malware.
  • Endpoint security that guarantees network endpoints (desktops, laptops, mobile devices, etc.) do not turn into an entry point for malicious activity.
  • Web security tools that eliminate web-based threats, block unusual traffic, and search for known attack signatures.
  • Tools that prevent spoofing by checking if traffic has a source address consistent with the original addresses.
  • Network segmentation that separates systems into subnets with unique security controls and protocols.

3.     Have Server Redundancy

Relying on multiple distributed servers makes it hard for an attacker to attack all servers at the same time. If an attacker launches a successful DDoS on a single hosting device, other servers remain unaffected and take on additional traffic until the targeted system is back online.
Since DDoS attacks work by overloading a server, a CDN (content delivery network) can share the load equally across several distributed servers.

4.     Look Out for the Warning Signs

If the security team can recognize the nature of a DDoS attack quickly, one can make a timely move and mitigate the damage.
Common signs of a DDoS are:
  • Poor connectivity.
  • Slow performance.
  • High demand for a single page/endpoint.
  • Crashes.
  • Uncommon traffic coming from a single or a small group of IP addresses.
  • A rise in traffic from users with a common profile (system model, geolocation, web browser version, etc.).
Please note that not all DDoS attacks accompany high traffic. A low-volume attack with a brief duration frequently goes under the radar as a random occasion. However, these attacks can be a test or diversion for a more hazardous breach (like ransomware). Hence, detecting a low-volume attack is as crucial as identifying a full-blown DDoS.

5.     Continuous Monitoring of Network Traffic

Using continuous monitoring (CM) to analyze traffic in real-time is an excellent technique for identifying traces of DDoS activity. The advantages of CM are:
  • Real-time checking ensures to detect a DDoS attempt before the attack takes full swing.
  • The team can build a strong sense of typical network activity and traffic patterns. When you know how regular tasks look like, it is easier to distinguish odd activities.

6.       Limit Network Broadcasting

A hacker executing a DDoS attack, probably sends requests to every device on a network to amplify the impact. A security team can counter this action by limiting network broadcasting between devices.

7.   Leverage the Cloud to Prevent DDoS Attacks

You can outsource DDoS prevention to a cloud provider as:
  • Cloud providers provide well-rounded cybersecurity, with top firewalls and threat monitoring software.
  • The public cloud has more bandwidth than any private network.
  • Data centers provide high network redundancy with copies of information, systems, and equipment.
DDoS threats are turning out to be riskier, but attacks are also expanding in number. Experts anticipate that the average number of yearly DDoS attacks will ascend to 15.4 million by 2023. That number indicates that almost every business will experience a DDoS sooner or later, so planning for minimizing the frequency and impact of this attack type should be at the top of your security to-do list.