What is Distributed Denial of Service attack (DDoS) UPDATED 2021

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What is Distributed Denial of Service attack (DDoS) UPDATED 2021

Distributed Denial of Service attack or DDoS attack is an attack in which many computers distributed on multiple networks send connection requests to a specific network or computer at the same time, overflowing the communication capacity and stopping functions.

DDoS attacks, one of the common cyber attacks, are relatively easy to perform, with many incidents in recent years. Exposure to serious attacks can severely damage the sales and reputation of a company or organization. Let’s discuss the attack in detail and explore ways to protect companies and organizations from DDoS attacks.

Understanding a DDoS Attack

DDoS attacks are attacks in which multiple computers send many processing requests via a network to a target server, causing the service to stop.

On the other hand, a DoS attack is a cyber-attack transferring too much traffic and data to a specific server or website called a Denial of Service attack.

Performing this DoS attack on a target website or server in large numbers from multiple computers is called a DDoS attack. So, DDoS is an extension of the Dos attack, in which the attacker hijacks multiple other computers and attacks the target all at once. A DDoS attack puts a heavy load on servers and network equipment so that websites cannot be accessed or network delays occur. The server automatically processes the information based on the information received. As a result, the process cannot catch up and get punctured, causing the server to go down (stop). As a result, targeted companies and organizations will suffer significant financial and credit damage.

Attacks can be broadly divided into several attacks targeting software or protocol defects and attacks that simply overload the server. In particular, in the latter case, unlike general unauthorized access, the transmitted packet does not look illegal, so there is no fundamental solution.

The attack is complicated by multiple zombie machines between the master computer and the target computer. To take fundamental countermeasures, it is necessary to identify the computer behind the scenes, which is difficult. In many cases, a zombie machine becomes a schematic for operating a zombie machine. Just as zombies bite humans and increase zombies, zombie machines create zombie machines.

How does a DDoS Attack Work?

The DDoS attack is a case where many attackers intentionally execute an attack all at once by recruiting participants on a bulletin board (BBS), or a computer or communication device is hijacked by the attacker participates in the attack without the owner’s knowledge.

In the latter case, the attacker infiltrates many computers unrelated to the target of the attack and sneaks a program (such as a Trojan horse) to execute the attack without the administrator or user’s notice. When an attack is started, a command to send connection request data is issued to a program that has been set up in advance. Since the compromised computer receives a request from the compromised computer, it is difficult to determine the computer’s true source of the attack.

DDoS attacks interfere with access that is difficult to distinguish from normal access, and it is often difficult to selectively eliminate them. For this reason, the damage will occur even if there is no management error, such as leaving a weak point in security at the target server. To prevent DDoS attacks, administrators and users of each computer must be careful not to launch malicious software on attackers.

The result is the same for Dos and DDoS attacks, as the targeted server is punctured or shut down.


The process works like the following example:

Corporate websites can stop exceeding load tolerance when access is concentrated, even without DDoS attacks. The university’s homepage is usually not so often accessed, but at the moment of announcing the examination results, the access is concentrated at once.

The server will then fail to withstand the load and stop. In this way, if the access is normally concentrated, the server can not process it, but Dos attacks and DDoS attacks do it intentionally.

Many universities distribute the processing by borrowing additional servers from outside only during such anticipated high load situations.

These measures are possible because the number of students who will access the system can be estimated, but the load cannot be predicted in the case of DDoS attacks.

Even if you increase the server specifications, the attacker will only increase the DDoS attack load.

What is the Goal Behind a DDoS Attack

The purpose of a DDoS attack is to prevent legitimate users from accessing your website. For a DDoS attack to succeed, the attacker needs to send more requests than the victim’s server can handle.

DDoS attacks will make online or website services unavailable by flooding them with malicious traffic from multiple computers. The attacker can then direct instructions and control the bots and ask the bots to pump traffic to a specific site: to the point that their bots stop working while taking the site offline.

DDoS attacks can last up to 24 hours, and good communication can ensure your business costs down during the attack.

It is often difficult to understand the motives or goals behind a specific DDoS attack or why it occurred. Since a hidden external source controls the attack device or computer, it is difficult to determine its source. When it is challenging to determine who is attacking, it is difficult to understand why. Therefore, many interpretations of the causes of DDoS are based on theories based on speculation or little evidence.

Governmental websites are a common goal of DDoS. Of course, it can be assumed that some people, organizations, and even other governments do not support the government. They may use DDoS as a form of electronic warfare to attack the government.

With the vast amount of information and resources available online, users with little technical knowledge can download and run simple scripts that implement DDoS attacks. Ordinary Internet users may just because they can attack large corporate sites. You may be able to close the site of a large company or organization to attract trivial ordinary computer users. For revenge, a personal conflict may cause some users to execute another user’s DDoS attack. Additionally, in online communities, including a “hacker community,” users who can successfully drop their goals may gain some form of fame or recognition in their community. However, they receive no fame in online societies, mainly due to their naive motivations.

Differences – DoS and DDoS Attacks

A DoS attack is a cyber attack that attacks from one computer. On the other hand, DDoS attacks have a difference in that they carry out cyberattacks from multiple computers at once. As a result, DDoS attacks send a much larger amount of data than DoS attacks and impose excessive load on the target.

In a DDoS attack, an attacker who takes intrusions into computer systems destroys programs or falsifies data and hijacks multiple general computers.

Taking over another person’s computer and using it in a cyberattack is called a “stepping stone.” As a result of this stepping action, the attacked websites and servers have the characteristic that it is difficult to identify the cyber attack’s attacker.

At first glance, the large amount of access received by a DDoS attack is indistinguishable from normal access. For this reason, it also has the advantage that it is difficult to eliminate only the access received by DDoS attacks selectively.

The difference between Dos and DDoS attacks can be easily understood by looking at the two attack alphabets’ meaning.

Dos attack: “Denial of Service attack.”

DDoS attack: “Distributed Denial of Service attack.”

“Distributed” is “spreading,” in which the attacking computer is spread into many computers.

DDoS attacks: DoS attacks on a large scale

A common form of DoS is called “Distributed Denial of Service” (DDoS). With this variant, cybercriminals do not operate from a single attack computer but rather load target systems through requests from several computers, which can be combined to form gigantic botnets. Such a network of computers can generate significantly more data traffic than simple DoS attacks, which are only carried out from a single system. Therefore, DDoS attacks have a drastic impact on those affected, who generally have little prospect of finding the actual source of the attack. Attackers who set up botnets of this type make use of special software agents, which are placed on insufficiently protected computers on the Internet and controlled centrally without the knowledge of the operator. Such “infection” often occurs months before the actual DDoS attack.

Denial of Service attack | DDOS

Can DDoS Attacks Steal Information?

DDoS is a malicious attempt to dump a target or its surrounding infrastructure with large Internet traffic, disrupting normal traffic to the target server, service, or network.

DDoS attacks cannot steal site visitor information. The sole purpose of a DDoS attack is to increase website resources. However, DDoS attacks can be used as a means of blackmail. For example, website owners can be required to pay ransom to attackers to stop DDoS attacks.

However, in some cases, information may be collected because of DoS. Here are some examples, but this is not exhaustive:

●      When the standby system is offline, the load balancer may cause internal subnet information leakage or internal computer name leaks.

●      Turning off database DoS first may cause the application to display the database drive type, connection username, or internal IP address via an error message.

●      Incorrect API implementation can lead to an “open failure” situation, in which the Single Sign-On Server DoS enables an attacker to log in without authentication or use local credentials.

●      In an “Advanced Persistent Threat” scenario, the DoS detection infrastructure may allow an attacker to remain undetected during other information gathering phases.

●      Likewise, DoS on the firewall management interface may hinder accident response from network management.

●      DoS may allow the main revocation services for attackers to continue to use the revoked or known credentials in extreme cases.

What Are the Signs of a DDoS Attack?

Every DDoS attack is based on a larger network of computers. In theory, this network can actually own the attacker – in practice, it is almost without exception the bot networks already mentioned, which often consist of hundreds of thousands of computers. Corresponding computers are infected with malware that enables cybercriminals to access them unnoticed. There are also increasingly IoT devices ( Internet of things) attacks such as routers, surveillance cameras, or digital video recorders, a crucial role that could also be exploited as bots in the recent past.

It is surprisingly difficult to judge that a DDoS attack has been made. A large amount of legitimate access happens to be the same as a DDoS attack. Careful judgment should be made as to whether or not this is a DDoS attack.

So, how do you know if your site is suddenly doing well to receive more traffic or if you are currently suffering from a DDoS attack?

There are two types of DDoS attacks. One is that communication itself is the same as the regular one, but the number of accesses is abnormally high. The other is that communication itself is abnormal. The response as a network administrator depends on which attack pattern.

If your website is down by an increase in legitimate traffic, this should usually happen only for a short period until the normal operations are restored.

You can also check your analysis tools to see if a particular traffic source continues to query a specific data set for a long time after the TTL (the time frame set by you to ignore held data to free up resources) has expired for your website.

Dns Spoofing | DDOS

Two main signs indicate that you are likely to be attacked by DDoS:

●      When the site is not available, the site is delayed.

●      When arriving on the website takes time.

The Amplification Effect of DDoS Attacks

A DDoS attack is launched using a DNS cache server accessible from the Internet as a stepping stone in the DNS amp attack. In order not to be used as a springboard, make the cache server unavailable from the Internet. For this purpose, access control is performed, or operation is performed separately from the content server.

DNS, which provides name resolution services on the Internet, is a fundamental service. Still, there is a concern that large-scale distributed denial of service attacks (DDoS attacks) using this service may occur. When a specially crafted DNS request is sent to a BOT (attacking computer), many DNS packets are sent to the attack target using the untreated DNS server as a “stepping stone.” As a result, the processing capacity and network lines become congested and saturated, and normal uses cannot be performed.

It is called a “DNS amp” because it can generate a packet that is often its size (amp = amplification) just by sending a small DNS request packet. This explains the mechanism of the attack.

Generally, a computer or service called a DNS server has two main functions. A “content server” provides DNS zone information to the outside world, and a “cache server” processes name resolution requests from clients. The latter accesses the DNS information provided by the content server.

DNS amp is a DDoS attack that uses this cache server function from the Internet side. Normally, it is unnecessary to use the cache server function from the Internet side, so it should be prohibited. However, DNS servers with DNS amp measures can use this function from the Internet side. The cracker who sets up a DNS amp finds such a DNS server and uses it as a springboard server.

What Happens During a DDoS Attack?

During a DDoS attack, many meaningless, incomplete requests or incorrect protocol elements, etc., are sent to the attacked network infrastructure. As a result, either the IT infrastructure (e.g., server) is overloaded, or the existing line capacity no longer offers sufficient bandwidth to handle real data traffic, for example, that of your customers.

This can make your website unreachable for your customers. The attacked Internet connections and the LAN components behind them become slow due to security measures (e.g., firewalls) overloaded and unreachable. The restricted or blocked accessibility quickly causes considerable economic damage to your company.

Among the most common or rare attack methods, the multi-vector attack has the highest risk potential. Here several methods of attack are simultaneously used, which increases the risk significantly for your business. Since automated systems can only offer limited protection against such complex attacks, specialized rescue teams often have to be formed to combat them, detect and combat the threat in several places.

Service layer DDoS attack

Attacks of this type are aimed at specific applications used by your system (HTTP, SSL, DNS, SMTP, SIP, etc.) and flood them with an excessive number of requests so that sessions can be exceeded. This overload then stops the processing of tasks in your applications.

ddos protection | DDOS

State-Exhausting DDoS attack

This type of attack is aimed at stateful security appliances (firewall, IPS, load balancer-ADC). It should lead to the session table overflowing or the maximum session setup rate being exceeded due to many requests. Due to this overload, system tasks can no longer be performed.

Types of DDoS Attacks

Several different DDoS attacks are still relevant in the current scenario.

The attackers use various methods in a distributed denial-of-service attack and do not always target vulnerabilities or gaps in the code of a website. It is quite easy to achieve the desired success through a concentrated attack against certain services in most cases. As a rule, a distinction is made between the following three types of attack, although it is important to note that there have been separate types in recent years. However, these would go too far and at least do not occur in most waves.

Skillful hackers can perform DDoS attacks with relative ease, and there are several types of DDoS attacks that can occur. The three main categories include:

●      Attacks from large amounts of data (volume-based)

●      Protocol attacks

●      Attacks on the application layer

Volumetric or Volume based DDoS attack.

This form of DDoS attack is one of the most widespread and popular forms of attack. An overload is generated on the carrier connection line until the capacity limits are exceeded and the system is paralyzed.

This attack attempts to cause congestion by consuming all available bandwidth between the target server and the larger cloud server or Internet. A large amount of data is sent to the target using a zoomed form or another method to create a large amount of traffic, such as ordering bots.

UDP floods

UDP flood attacks are still the most popular type of DDoS attack. During this attack, ports are flooded with UDP packets (user datagram protocol), which leads to the host returning diagnostic information that the destination cannot be reached. If ports are flooded with huge UDP packets, it can ultimately lead to the host being overwhelmed and no longer accessible.

ICMP floods or Ping floods

This is another common attack that overwhelms a computer with ping packets, also called ICMP echo packets. Usually, one request packet follows the next very quickly, and since an answer is generated for each request, the system is ultimately overloaded.

Protocol-based DDoS Attacks

Protocol attacks (called the state-exhaustion attacks) create service outages by consuming all the status table capacity available for web application servers or intermediate resources such as firewalls and load balancers. Protocol attacks use the vulnerabilities in layers 3 and 4 of the protocol stack to make the target inaccessible.

The exploitation of software errors and security gaps

If an attacker is aware of certain security gaps in an operating system or program, DoS and DDoS attacks can be designed so that inquiries trigger software errors and even system crashes. Examples of this type of attack are the Ping of Death and Land attacks.

Ping of Death

This attack pattern aims to crash the affected system. Attackers make use of implementation errors of the Internet Protocol (IP). IP packets are usually sent as fragments. If incorrect information is sent for the packets’ assembly, some operating systems can be tricked into generating IP packets larger than the maximum permissible 64 KB. This can lead to a “buffer overflow” in which too much data ensures that adjacent memory locations in the target memory area are overwritten.

SYN Flood | DDOS

Land attack or SYN Flood

In the event of a land attack, an attacker sends an SYN packet as part of the TCP three-way handshake, the destination, and the sender address, which corresponds to the server to be attacked. As a result, the server sends the response to the request to itself in an SYN/ACK packet. This can be interpreted as a new connection request, which in turn must be answered with an SYN / ACK packet. This creates a situation in which the system continuously answers its own queries, leading to a massive workload or even a crash.

A good “three-way handshake” goes something like this: The server receives an SYN packet, sends an SYN-ACK packet back; The client then sends an ACK packet to the server. An SYN flood attack tries to disrupt this process. The attacker sends several SYN packets, but then no ACK packets are sent back to the server, which means that the process is not completely completed, which leads to a fault.

SYN Flood is the same as a supply room worker who receives a request from the store’s front desk. The worker receives a request to receive the parcel, then awaits confirmation before the parcel is taken out. The staff will then receive more parcel requests without confirmation so that they can not afford any parcels, they are confused, and they ask to leave the start unattended.

The attack uses a TCP handshake by sending many SYN packets “Initial Connection Request” with a phishing source IP address to the target. The target computer responds to each connection request and then waits for the last step in handshaking (this process never occurs), which depletes the target resources in the process.

Application Layer Attacks

Sometimes called a Level 7 DDoS attack, these attacks’ goal is to deplete the target’s resources. The attack is directed at the layer that creates web pages on the server and responds to HTTP requests. The cost of executing one HTTP request on the client is low, and the target server response cost is also high because the server usually has to upload multiple files and run database queries to create a web page. Layer 7 attacks are difficult to defend because they are difficult to distinguish as being harmful.

With a simple attack on the network, the attackers use the infrastructure of most servers and routers. With the help of fictitious and manipulated requests to the network, such a load is reached quickly that most devices switch off. In this case, a website would no longer be accessible or could only be reached very slowly. Due to the attack duration, it is also likely that individual services will shut down for security reasons.

Attacks targeting the DNS server

DNS servers are a popular target for attacks. This is because a successful attack within a short period of time means that no server services can be reached. For this purpose, manipulated data or a pure mass of queries are used, which overwhelms the DNS server.

DNS Amplification is like someone calling a restaurant who orders all available dishes and then tells the restaurant to call again and tell the entire order. The phone number of the callback provider that is providing is the target number. With a little effort, a longer response can be produced.

By submitting a request to an open DNS server using a phishing IP address (the target’s real IP address), the server’s target IP address will respond. The attacker creates the request so that the target DNS server responds with a large amount of data. As a result, the target received an amplification of the attacker’s initial query.


HTTP Flood

With this type of attack, a server is flooded by the attacker with HTTP requests. Due to the high number of requests, the server can no longer respond to normal requests and responds to requests from users with denial of service.

HTTP flooding initially appears as if millions of users had decided to visit the website within a few seconds for normal servers. Suddenly, millions of requests flood the server, which at first glance seem like normal visits. Due to the amount of access and the fact that there are now learnable algorithms for the attacks, the server is usually switched off at some point, and the page is no longer accessible.

This attack is the same as pushing the refresh in a web browser repeatedly on many different computers – HTTP requests flooding the server, causing a denial of service.

These attacks range from simple to complex. The simplest application can use the same range of attack IP addresses, referring URLs, and a user agent to access the URL. Complex versions may use many abusive IP addresses and use random referrals and user-agents to identify random URLs.


If many connections are sent to a web server and kept open for a longer period of time, it is known that this can crash. The Slowloris software keeps as many connections as possible open for as long as possible. These incomplete requests mean that the webserver is overwhelmed and has to reject requests from users.

The effect of these various DDoS attacks is usually always the same: at some point, either hardware or software fails, and the website, the server, or the entire network comes to a standstill. Depending on the company or institution behind this system, this can lead to critical situations. Various security measures reduce impact and risk but do not allow such a situation to be prevented entirely.

What is the Motivation Behind DDoS Attacks?

To understand why such attacks have been occurring more and more frequently in recent years, one only has to look at the possible motives of attackers. In the early years, the DDoS attack was mostly a form of vandalism against websites. As a result, popular browser games, for example, were switched off when they published unpopular innovations. Newspapers were also a popular target for reporting. However, it has recently been shown that the distributed denial of service attacks has become a tool for politics and crime on the Internet.

Like all hacks, DDoS attacks are often only carried out to attract attention and put the hackers in the spotlight. But many high-level attacks require a ransom. In return, it is offered that the attacks be stopped when a certain amount is paid. This doesn’t have to happen until an attack has already taken place. Some extortionists threaten attacks and charge a certain amount so that they are not carried out in the first place. However, many of these extortion attempts have not been successful.

Companies at risks

Any industry or company, regardless of its size, can fall victim to a DDoS attack. The question is not whether but when an attack on your own company occurs and how quickly it is discovered. Cybercriminals and blackmailers focus on e-commerce companies, banks, FinTech companies, insurance companies, manufacturing companies, the media, and healthcare. Data centers and organizations from the public sector are also popular targets for DDoS attackers. The criminals’ motives go far beyond ransom demands: With their attacks, they want to paralyze production facilities and production processes, interrupt the electricity or energy supply, and influence reporting.

Every company has its own vulnerabilities, which make it vulnerable. Some companies are more susceptible to DDoS attacks than others. Any company that relies on doing business on the Internet should take precautions to protect against DDoS attacks. It makes sense to evaluate how much the company would be economically affected if, for example, the website were down for a few hours or even a whole day. Which systems would be affected, and how important are they? Every hack and attack on a company’s service can also cause customers to lose confidence in the company. This is particularly the case with online shops, where customers may hesitate to shop for security reasons – whether justified or not.

DDoS for Ransom

Over the past few years, it has been heard repeatedly that DDoS attacks, such as online shops or social media platforms, have paralyzed them. The attackers demanded a sum to reaccess the websites and that the loss of sales and image could not be increased.


Self-proclaimed activists from various political and social backgrounds have already shown their protest in this form. While the PETA website was already affected, animal rights activists have paralyzed the meat shops’ online shops. Most of the time, such attacks don’t last, but they do damage.

Targeted attacks

A very new phenomenon is the targeted deactivation of government websites and infrastructures on the net. In particular, Russia and North Korea are repeatedly suspected of such attacks, and, certainly, western intelligence agencies have already used such attacks.

Pure Boredom

There are also examples of simple vandalism that use pre-built programs to harm another person. Stricter legislation has only made these cases rarer, at which point cybercrime has increased.

Impact of DDoS Attacks on Site Owners

The principle of DDoS attacks is as simple as it is successful – and painful for the victims. Cybercriminals direct more data traffic to an IP address than process and bring the server to its knees. In September 2016, hackers directed around one terabyte of traffic per second to a French host server, breaking the previous data record.

The consequences of a DDoS attack can be devastating: the webshop is offline, the e-mail server no longer receives and sends e-mails, and the employees are unavailable. A drop in sales and a loss of reputation can cause lasting damage to the company and disrupt customer confidence. It is not uncommon for a DDoS attack to be followed by blackmail attempts, with the threat of paralyzing the systems again.

An attack always harms affected companies and institutions, regardless of the method chosen. Organizations affected still suffer from the consequences years later. Efficient DDoS protection is therefore critical.

Economic damage | DDOS

Economic damage

Being offline for a few minutes quickly costs several thousand euros. Loss of profits and lost marketing budgets are only part of the financial damage.

Downtime of just a few seconds has a huge impact. The longer the slowdown period takes, your company can cost tens of thousands of euros in lost sales. A weakening time of hours can go into hundreds of thousands of euros, not to mention damage to reputation.

Image damage

After a successful DDoS attack, the loss of reputation is incalculably large. Reconstruction takes a lot of resources and can take years.

Data theft

During a DDoS attack, the systems no longer work in the usual way. Under high or overload conditions, some systems suddenly become vulnerable and open up new attack vectors.

Sometimes an attack is short-lived, and the “exposure time” only lasts until the weakening begins. The impact of an attack is usually felt much longer. It is also important to note that many DDoS protection services take time to identify an attack before they even begin to counter it.

A critical factor for affected websites from DDoS attacks is the time to mitigation. TTM begins when the first DDoS attack packet reaches your system and continues until your DDoS defense service begins to clean up the incoming data traffic.

TTM is very different among service providers. Therefore, it is important to understand what protection you can expect, especially if business operations are heavily dependent on uptime. This is particularly relevant for financial services and e-commerce companies.

How to Prevent DDoS Attacks

The main problem with DDoS Attack Mitigation is the distinction between attacks and normal traffic. For example, if a website launching a product is full of enthusiastic customers, cutting off all traffic is a mistake. If sudden company traffic comes from poorly known actors, steps may be necessary to mitigate the attack. The difficulty lies in distinguishing between real customers and offensive traffic.

In the current day Internet, DDoS traffic comes in many forms. Traffic can vary in design, from unidentified single-source attacks to complex adaptive multi-factor attacks. Multi-factor DDoS attacks use multiple attack methods to overwhelm the target differently, which could divert mitigation efforts on any single pathway. An example of a multi-vector DDoS is an attack that simultaneously targets multiple layers of the protocol stack, such as DNS amplification (the 3/4 target layer) and HTTP flow (target layer 7).

Ways to protect

There are ways to protect yourself against DDoS attacks so that you don’t have to be at the mercy of them: the so-called scrubbing center can analyze the data traffic that leads to a website and prevent malicious attacks at an early stage. To combat a possible protocol attack, the traffic can also be analyzed and stopped, and potential attackers can be stopped from the start.

Programs and service providers that protect against DDoS attacks, for example, analyze visitors’ behavior to the website, take action against bots or investigate suspicious phenomena to act against and protect against possible threats.

In general, it can be said that there are no “simple” protection methods against such attacks. Since this is actually organized crime on the Internet, which is often associated with the appropriate intentions behind it, most attackers have the appropriate professionalism to undermine normal systems.

A good service provider can achieve most measures for server housing or hosting. These providers have technical and software-based solutions for protection. For example, this includes good filtering of requests to the server and good routing with a correspondingly distributed load distribution. This is also possible through clusters and virtualization.

However, it already begins to close unused services for simple owners of a server and pay attention to the ports on its own server. The best protection against an attack is to offer as little attack surface as possible for DDoS. All measures beyond this should be discussed individually for your own system with good hardware and the appropriate advice from IT experts.

DDoS-Attack | DDOS

Various security measures have been developed to counteract the overloading of IT systems by DoS and DDoS attacks. Starting points offer the identification of critical IP addresses and the closing of known security gaps. It is also important to provide hardware and software resources that can be used to compensate for minor attacks.

Mitigating multi-vector DDoS attack

Canceling out multi-factor DDoS attacks requires multiple strategies to deal with different development paths. Generally, the more sophisticated the attack, the more difficult it is to separate traffic from normal traffic – the attacker’s goal is to integrate as much as possible, which reduces the mitigation efficiency. Mitigation attempts that involve dropping or restricting traffic indiscriminately may ignore good traffic, and attacks may also modify and adapt to evasive countermeasures. To overcome complex deactivation attempts, a layered solution will bring the greatest benefits.

Have a WAF to protect from DDoS attacks

A DoS attack puts a load on a target website or server by sending many packets. As a defense measure, it is a method to identify and block the IP address that launches a DoS attack by introducing a firewall, server, and network traffic monitoring system that supports the DoS attack.

Web Application Firewall (WAF) is a tool that can help mitigate DDoS layer attacks. By placing a WAF between the Internet and the original server, the WAF can act as a reverse proxy, protecting the target server against certain types of malicious traffic. By filtering requests based on a series of rules used to define DDoS tools, you can stop Layer 7 attacks. The key value of WAF Effectiveness is the ability to implement custom rules to respond to attacks quickly.

Black Hole Routing

The solution available to almost all network administrators is to generate a black hole track and flood the traffic on this track. In its simplest form, when blackhole filtering is performed without specific restrictions, both legitimate and malicious network traffic will be directed to blank roads or black holes and dropped from the network if DDoS attack the Internet feature, the property’s Internet Service Provider (ISP) may send all traffic to the site in a black hole as a defensive measure.

Rate Limiting Steps – Block Application Layer DDoS Attacks

Application-level DDoS attacks are designed to attack the application itself, focusing on specific vulnerabilities or issues that prevent the app from delivering content to users.

Reducing the number of requests the server accepts in a given time frame is also a way to mitigate service attack denial. Although price curbs can help slow the rate of web crawlers steal content and reduce brute force login attempts, the rate curb alone may not be enough to respond effectively to complex DDoS attacks. However, the rate reduction is a useful part of an effective DDoS mitigation strategy.

Anycast Network Diffusion

This resolving method uses the Anycast network to spread attack traffic across the distributed server network until it absorbs traffic. Just like directing an accelerating river into a smaller, separate channel, this method deploys the impact of distributed attack flows at a manageable level, thereby dispersing any destructive capabilities.

Anycast reliability in DDoS attacks depends on attack size, network size, and efficiency.

IP blocklists

Blocklists make it possible to identify critical IP addresses and to discard data packets directly. This security measure can be implemented manually or automated through dynamically generated blocking lists via the firewall.


To filter out conspicuous data packets, it is possible to define limit values for data quantities in a certain period. However, it should be noted that proxies can sometimes cause many clients with the same IP address to be registered with the server and possibly blocked for no reason.

The providers offer an alternative. You can evaluate the data traffic in the network’s backbone and prevent the traffic in the case of conspicuously large data traffic towards an IP address. The provider coordinates the method closely with the attacked company.

For example, in so-called blackholing, experts delete all traffic that goes to an IP address not used by the customer and thereby relieve the connection. Filter lists also have a corresponding effect. The company determines senders who can reach the connection, and all other requests are rejected. Another method is a virtual machine that marks and discards malicious IP packets in the customer’s data traffic so that only clean traffic hits the customer’s connection. The company can work without any problems.

SYN cookies

SYN cookies target security gaps in TCP connection establishment. If this security measure is used, information about SYN packets is no longer stored on the server but is sent to the client as a crypto cookie. While SYN flood attacks take up computing capacity, they do not use up the target system’s memory.

Load balancing and CDN

An effective countermeasure against overload is load distribution across different systems, as is made possible by load balancing. The hardware utilization of services provided is distributed across several physical machines. DoS and DDoS attacks can be absorbed to a certain extent.

DDoS has the intention to overload the server of the host. One solution is to store your data on multiple servers around the world. This is exactly what a content distribution network does.


CDNs (Content Distribution Networks) provide users with your website or data from a server that is close to each user for faster performance. But that means you are also less vulnerable because you have many others still running when one server is overloaded.

Country blocking

Often, country-based blocking can effectively reduce risk. It can also help comply with certain regulatory policies aimed at “stopping hackers.” Here are some things to note:

Not that a state blockade will help stop DDoS threats, but it is important to understand what the blockade means to the whole world except your country. It may not persuade you like other solutions. Country Blocking is a way to enhance practical protection against DDoS attacks such as firewalls on the website.

The region’s origin is not related to the computer; the website firewall can only see the IP address. Inferring your geographic location from IP addresses is based on large tables that are not completely updated.

Today, most Android networks consist of thousands of hacked websites, infected CCTV, infected computers, and other Internet of things devices. Attacks all over the world. However, a country blockade can prevent thousands of unwanted tracking software from sending spam to your contact log. Definitely a bonus!

Treating these blocking systems is trivial for attackers. Some forms of anonymous proxy or proxy may be used outside of the list of banned countries, which occurs “naturally” when using Tor, a free open source program to enable anonymous communication.

What to Do in a DDoS Attack?

Even if a situation that seems to be under a DoS attack occurs, it is not uncommon for the server to stop functioning due to other causes. Because it is challenging to determine and the analysis is also expensive, the use of dedicated equipment is the most reliable and, as a result, the cost.

However, as mentioned above, DoS attacks are often performed for protests or harassment against companies and organizations. In such a case, even if a special device was introduced and the attack could be stopped once, the attack would be performed differently.

Monitor Traffic

DDoS attacks are among the most feared, but they are inherently rare. So if your internet goes down, check your connection before you panic about a possible attack. You can start by checking your router and checking the connection between your computer and the network. You may also monitor whether certain services (like Twitter) are down. These occur frequently and are rarely indicative of a DDoS attack.

It’s important to know exactly what normal, low, and high traffic is for your organization. If you know what to expect when your traffic reaches the upper limit, you can set a limit. This means that the server only accepts as many requests as it can handle.

Staying up to date with your traffic will also help you identify problems quickly. You should also be prepared for traffic waves due to seasons, marketing campaigns, etc. A lot of allowed traffic (from a viral social media link, for example) can sometimes cause the server to crash. And even if a legitimate source causes it, downtime can still be costly for your company.

Get more bandwidth

Once you have a good idea of how much server capacity you need based on your average and high traffic, you should secure it and more. Having more server bandwidth than you actually need is called over-provisioning.

In the event of a DDoS attack, this gives you more time before your website, server, or application is completely flooded.

Possibility of other attacks

DDoS attacks may be accompanied by other cyber attacks such as phishing. Since your website is down or offline, it becomes vulnerable to other threats, and information on your site may be compromised. Look for other possible cyber attacks and address the issue at the same time while dealing with DDoS attacks.

Local hard drive backup

With the sudden surge in technological improvements, everything in the cloud increases. And while this is extremely convenient to use, it is scary when the likelihood of a DDoS attack is high. For example, if you use Google Docs for work, all of your files are in the cloud. Also, Microsoft’s online version of Word is only synchronized with your PC if you have an active Office 365 subscription.

Local Backup Drive | DDOS

To be protected against malware on your computer, keep a local backup of all your important files – documents, media, photos – on an external hard drive. And repeat this process every week or a few weeks.

Call your hosting provider.

If the server for your data belongs to someone else or is operated by someone else, you should report the attack to this person immediately.

You could potentially move your traffic into a black hole until the attack subsides so that incoming server requests simply dry up, whether they are allowed or not. This is in their interest so that the servers of other customers do not crash.

From there, they route the traffic via a “scrubber” to filter out the illegal traffic and only allow normal requests.

If the company notices a DDoS attack, it should contact the provider as soon as possible to initiate countermeasures immediately, and the failure remains as low as possible. The experts guard the connection for the duration of the attack, which can last for several weeks. This allows them to adapt their methods at any time if the cybercriminals change their technique. If the attack has visibly subsided, the provider switches on the original routing, and the customer has a transparent Internet connection again. Filter lists can remain active.

Ask for help if necessary.

With attacks increasing year by year and the need to protect systems from these attacks, it is more important to contact a professional organization aware of the problem. DDoS attacks are an expensive problem, but it is simply the price you pay for hosting your company or your interests on the Internet. Every minute that your page cannot be opened, direct drop-in earnings could have been achieved in a normal situation. Protection should appear justified when viewed in this way.

Get ready to respond accurately and .promptly

If you experience a DDoS attack, you will likely not have enough time to respond to the situation before it is largely overwhelming. All of your services and applications will be downgraded or disabled, and quick recovery is your first step in the recovery process. In a crisis in which there is a deadline in which everyone works better, and further measures have already been defined. Put a team together, talk about your answer, and write down the plan. Be prepared.

How can you protect yourself against DoS attacks?

Hardly is the sobering answer, aside from checking that your computer is not part of a botnet (install an antivirus, improve router security, and update the passwords of your connected device). So you are not directly contributing to an attack. It is beyond your control to prevent this. And even without being part of such a structure, you cannot do much if your computer is one of the “reflected” devices, as this trick takes advantage of legitimate computer practices.

DoS attacks will not simply go away; this cannot be changed.

While we usually don’t get upset about online attacks, DoS attacks take an exceptional place in the online threat landscape. They are tools of oppression on the one hand but also tools of protest on the other. They are an undeniable evil but a much smaller one than data leaks and doxing. Although they harm ordinary people, these ordinary people are never the target of the attacks. While we would like to live in a world without DDoS attacks, it would be even better to live in a world where these attacks are unnecessary.

DDoS attacks are malicious attempts to disrupt the availability of a website or web application for users by flooding them with an enormous traffic, causing the website to collapse or slow performance. DDoS attacks are among the oldest threats to websites, but they are constantly evolving, making their defense significantly more difficult. Today, attackers use large armies of automated “bots.” These are computers that have been infected with malware and can be remotely controlled by hackers to launch large-scale DDoS attacks.

As DDoS attacks become more extensive and sophisticated, their defense is becoming increasingly difficult. DDoS attackers’ focus has shifted from the network to the application level, where DDoS attacks are more difficult to detect. DDoS attacks are often used as camouflage to divert IT teams’ attention from other simultaneous attacks. Even for the largest companies, it is almost impossible today to create an adequate infrastructure with scaling options in response to a large DDoS attack. As a result, many companies looking for DDoS protection are now turning to cloud-based solutions.

Sit it out

Hiring a professional to redirect and filter your web traffic is expensive. Most DDoS attacks are over after a few days (even if they can take longer in serious cases), so you always have the option of simply accepting the loss and preparing better next time.

Be prepared

Your organization should be prepared for significantly more web traffic or server requests than you actually need. Stay on the safe side.

The best solution is to prevent the risk of a DDoS attack from the outset. You can do this by installing a good antivirus that protects you from malware. A CDN and the setting of a limit based on normal traffic are other great preventive measures.

Prevention is always a better option because once a DDoS attack is on the go and your server is offline, it can be expensive to get back to normal – the downtime of your website can harm your sales and reputation. So make sure that your company is prepared for all types of attacks.

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Secure Your Website from DDOS Attack - Webcybersecure June 14, 2021 - 8:52 pm

[…] The cloud providers monitor your website’s traffic and analyze it in order to detect the attack. DDoS mitigation is one of the most popular methods of detecting a distributed denial of service attack and […]


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