What is a DDoS Attack and How It Works

A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt the normal traffic of a targeted server, service, or network. It overwhelms the system with an excessive amount of internet traffic, preventing users from accessing the services and website. This type of attack has become increasingly common in recent years as attackers look to exploit vulnerabilities in websites and networks to cause widespread disruption. Only in 2022, the world had nearly 13 million DDoS attacks

Organizations need to take steps to protect themselves from DDoS attacks. These include investing in secure network infrastructure, implementing layers of defense such as firewalls and intrusion prevention systems, monitoring their networks for unusual activity, and having an incident response plan in place in case of an attack.

What is a DDoS attack?

According to a Netscout report, there are 3,500 DDoS attacks per day or 145 per hour, with a duration that ranges from less than five minutes to over 12 hours. But, what exactly is a DDoS attack and how can it damage your business? A distributed denial-of-service (DDoS) is a type of cyberattack that overloads servers, making it difficult or even impossible for users to access websites. However, this is not a recent type of cyber threat. The first deliberate DDoS attack was in 1973 when a student misused a remote peripheral access command to lock up terminals in a single computer lab. 

DDoS attacks are getting more common and increasingly harder to mitigate, as the attackers develop more sophisticated ways to conduct the attacks.

What is the difference between DDoS and DoS?

DDoS and DoS attacks are similar in that they both involve flooding a target with requests or traffic to disrupt its services. The key difference is that DDoS attacks use multiple distributed sources of traffic, while DoS attacks originate from a single source.  

Additionally, DoS attacks can be easier to defend against than DDoS attacks as the attack vector is limited and fewer points require protection.

How does a DDoS attack work?

A DDoS attack works by flooding the target with more requests than it can handle, causing it to either become unavailable or extremely slow.  

The attacker will usually use a range of computers to generate these requests and make them appear legitimate. This means that even if the origin of the attack is detected, it is difficult to hold the attackers accountable as they are not directly responsible for the malicious traffic.

Anatomy of DDoS attacks

During DDoS attacks, several vectors are used to disrupt the organization’s natural traffic. The three more common vectors are:

  • TCP Ack (transmission control protocol acknowledgment)
  • TCP Syn (transmission control protocol synchronized)
  • DNS Amp (domain name system amplification)

The attackers will both change and add vectors during the attack. Also, it will originate from ports across the world, meaning that a single event comes from different countries. Since the attacks shift while it’s happening, mitigation actions are very hard to apply. Yet not impossible. 

The main way DDoS attacks work is through botnets. The attackers will hack computers and install bots on them, that is code or malware. Then they use these bots to form an infected network called botnets. With this network formed by computers distributed across countries and continents, the cyber attackers will then overwhelm the victim’s servers and disrupt their services.

What are botnets?

A botnet is a collection of computers that have been infected with malicious software and can be used to launch DDoS attacks. Attackers gain access to these computers by installing malware or exploiting vulnerabilities in outdated software. Once the attacker has control of the computers, they can use them as part of their DDoS attack.  

The computers in the botnet are usually split across multiple countries and continents, making it difficult for authorities to identify and shut down the source of the attack.
Botnets can also be used for other nefarious activities such as sending spam emails, stealing data, or committing fraud.

Types of DDoS attacks

Despite having many types of DDoS attacks, they are classified according to the network connection layers they target into three main categories:

  • Volume-Based or Volumetric Attacks. The goal of this type of DDoS is to increase bandwidth between the victim and the larger internet. They usually work through a DNS Amp vector that amplifies the attacker’s small query. An example of a Volumetric Attack is the DNS amplification attack.
  • Protocol Attacks. This type of attack consumes the available capacity of web servers, including its firewall. Most protocol attacks use TCP Syn vector to overwhelm the victim’s server with internet requests. An example of a Protocol Attack is the SYN Flood.
  • Application-Layer Attacks. This type of attack works as if the web page is being constantly refreshed. As a consequence, the server has to handle more processes than it usually does. An example of an Application-Layer Attack is an HTTP flood attack.

How to identify a DDoS attack

Some symptoms of a distributed denial-of-service can happen organically, like slow pages or increased traffic. For this, you must take a further look to see what is happening to your website and server.  

The most commons symptoms to identify a DDoS attack:

  • Unavailable web page
  • Unexpected spikes in traffic
  • Odd hours of the day spikes of traffic
  • Slower page load time
  • Inability to access certain web pages or services
  • An unexplained surge in requests to a single page or endpoint
  • The web server is unresponsive for no apparent reason
  • Timeouts when attempting to connect to the affected resource
  • Multiple connections from multiple IP addresses that don’t normally visit the website or application
  • Unexplained increase in requests from a single source or geolocation
  • Unusual traffic patterns as regular spikes of traffic

What are the motivations for DDoS attacks?

The motivations behind a DDoS attack can vary. They often include political or social motivations, such as protesting against a government or company policy, as well as financial gain and revenge.  However, some attackers use DDoS attacks simply to cause disruption and chaos or incite fear.  

Since the attacks can be random and as many companies welcome traffic spikes, it’s nearly impossible to prevent a DDoS attack. Because of it, an incident response plan is the best way to prevent further damage during a distributed denial-of-service attack.

What to do after a DDoS attack?

As soon as you get suspicious your server is having unusual traffic, you must take action to determine if it’s a DDoS attack and follow your recovery plan. If you don’t have a plan, then follow the next steps. 

1. Detection

Check your server for unusual requests and look for any of the symptoms of the attack. Early detection can prevent further damage to your business. 

2. Filtering

Filter the traffic to redirect and contain harmful requests to prevent an overload system. CAPTCHAs and cookies can help you prevent bot connections. 

3. Mitigate the attack
After that, as you contain the flood on your page, you must take proactive steps to eliminate the threat and regain control over your server.

How to mitigate DDoS attacks?

The best way to mitigate DDoS attacks is to have a comprehensive defense solution in place. This should include a combination of network security measures, such as firewalls, intrusion detection and prevention systems, and anti-DDoS solutions. Having an understanding of the attacker’s methods can help you develop strategies that can help disrupt their attack or minimize its effects. 

Enterprises and organizations must take a few actions to mitigate a  distributed denial-of-service attack.

1. Risk assessment

Risk assessments and audits may not completely avoid a DDoS attack, but conducting it on your devices, servers, and network lets you know the vulnerabilities in your organization’s software and hardware.
Once you know the most vulnerable elements of your network, you can decide which security strategy to implement. This can lessen the damage and disruption that a DDoS attack imposes.

2. Traffic differentiation

Try to identify the source of the bad traffic generated by the bots. Since you can’t shut down all the traffic, as you may lose real clients and users, you can share the attack traffic across a network of distributed servers.

3. Black hole routing

You can mitigate the attack by creating a black hole route. This will push traffic into the black hole. However, in this strategy, all traffic, both good and bad, is affected and routed to a null route and dropped from the network.

4. Rate Limiting

One more way to mitigate DDoS is by limiting the number of requests a server can accept within a specific time frame. Even though this can’t prevent more sophisticated attacks, you can block most of them.

5. Firewalls

Many enterprises apply Web Application Firewall (WAF) as a security measure. It acts as a reverse proxy as it works between the company’s servers and the internet setting rules to filter requests.

How Proven Data can help you

Proven Data offers cybersecurity services to help you protect your servers, website, and data. Contact an expert 24/7 to request a quote and guarantee extra protection for your business.

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