DOS AND DDOS ATTACKS

What is a Denial of Service (DoS) Attack?

A DoS attack is a type of denial of service assault in which a machine floods a server with TCP and UDP packets.

During this form of assault, the service is rendered inoperable because packets sent over the network overload the server’s capabilities, rendering the server inaccessible to other devices and users on the network. DoS attacks are used to disable particular devices and networks, preventing other users from accessing them.

DoS attacks may be carried out in a variety of different methods. These are some examples:

Buffer overflow assaults — The most prevalent sort of DOS attack encountered. In this assault, the attacker floods a network address with traffic, rendering it inoperable.

Ping of Death or ICMP flood – An ICMP flood attack employs unconfigured or incorrectly configured network devices to broadcast spoof packets to ping every machine on the target network. This is called a ping of death (POD) assault.

SYN flood – SYN flood attacks attempt to connect to a server but fail to finish the handshake. As a result, the network gets overburdened with connection requests, preventing anybody from connecting to the network.

Teardrop attack — A teardrop DoS attack involves an attacker sending IP data packet fragments to a network. The network then tries to reconstruct these pieces into their original packets. The process of assembling these fragments exhausts the system, causing it to crash. It crashes because the fields are meant to confuse the system and prevent it from reassembling them.

Because of the simplicity with which DoS assaults may be orchestrated, they have become one of the most prevalent cybersecurity dangers that modern enterprises must deal with. DoS assaults are simple yet powerful, and they may cause catastrophic harm to the organizations or persons targeted. An organization can be rendered inoperable for days or even weeks because of a single attack.

The amount of time a company spends offline accumulates. Every year, firms lose thousands of dollars due to network outages. Although no data is lost, service disruption and downtime might be significant. One of the most basic criteria for remaining safe in the modern day is the prevention of DoS assaults.

What is a DDoS attack?

One of the most prevalent forms of DoS attack used nowadays is a DDoS assault. During a DDoS attack, several systems send malicious traffic to a single system. The attacker may take the system offline more quickly by attacking it from many places.

The reason for this is that the attackers have a higher number of devices at their disposal, making it difficult for the victim to determine the source of the assault.

Furthermore, employing a DDoS assault complicates the victim’s recovery. Nine times out of ten, the systems used to conduct DDoS assaults have been hacked, allowing the attacker to initiate strikes remotely via slave machines. Zombies or bots are the names given to these slave computers.

These bots link to establish a network of connected devices known as a botnet, which is administered by the attacker via a command and control server. The attacker or botmaster can coordinate assaults via the command and control server. Botnets can range in size from a few dozen to hundreds of thousands of bots.

DoS and DDoS Attacks of Various Types

DoS attacks for bringing down networks may be classified into several major types. These take the form of:

Volumetric Attacks – A volumetric attack is any type of attack in which an attacker consumes a target network’s bandwidth resources on purpose. Once network bandwidth has been spent, it is no longer available to genuine network devices and users. When a volumetric assault occurs, the attacker floods network devices with ICMP echo requests until there is no more accessible bandwidth.

Fragmentation attacks are any type of attack that compels a network to reassemble altered network packets. During a fragmentation attack, the attacker delivers modified packets to a network such that they cannot be reassembled when the network attempts to do so. This is due to packets containing more packet header information than is allowed. As a result, packet headers are too big to reassemble in bulk.

TCP-State Exhaustion Attacks — In a TCP-State Exhaustion attack, the attacker attempts to limit the number of connections that they may make by targeting a web server or firewall. The goal of this type of attack is to drive the device to its maximum number of concurrent connections.

Application Layer Attacks – Application layer or Layer 7 attacks target applications or servers in an attempt to consume resources by launching as many processes and transactions as feasible. Application layer assaults are very difficult to identify and respond to because they do not require many devices to begin an attack.

DDoS Attacks in Their Most Common Forms

DDoS assaults are the more complicated of the two dangers since they employ a variety of devices that raise the intensity of attacks. Being attacked by a single computer is not the same as being attacked by a botnet of 100 machines!

Being familiar with as many diverse attack types as possible is part of being prepared for DDoS attacks. In this part, we’ll go through them in further depth so you can understand how they’re utilized to harm corporate networks.

DDoS assaults can take several forms, including:

Ping of Death (POD) – A Ping of Death (POD) attack involves the attacker sending repeated pings to a single machine. POD attacks employ modified packets to deliver packets to the network that contain IP packets that exceed the maximum packet length. These unauthorized packets are delivered in pieces. Once the victim’s network’s network resources are depleted from attempting to reassemble these packets, they are no longer available to genuine packets. This brings the target network to a halt and renders it inoperable.

UDP Floods – A DDoS attack that floods the victim network with User Datagram Protocol (UDP) packets is known as a UDP flood. The attack operates by flooding ports on a remote host, causing the host to continue seeking an application that is listening on the port. When the host detects that there applies, it responds with a packet stating that the destination could not be reached. This drains network resources and prevents other devices from connecting successfully.

Ping Flood – A ping flood attack, like a UDP flood attack, employs ICMP Echo Request or ping packets to disrupt network functionality. The attacker transmits these packets quickly without waiting for a response to render the target network unavailable via brute force. These attacks are especially dangerous since bandwidth is spent in both directions, with targeted servers attempting to respond with their own ICMP Echo Reply packets. The final effect is a decrease in network speed across the board.

SYN Flood — Another sort of DoS attack in which the attacker leverages the TCP connection sequence to render the victim’s network inaccessible. The attacker sends SYN queries to the victim’s network, which replies with an SYN-ACK. The sender is then expected to react with an ACK response, but the attacker does not (or uses a spoofed source IP address to send SYN requests instead). Every unanswered request consumes network resources until no devices can connect.

Slowloris – Slowloris is a form of DDoS attack software created by Robert Hansen aka RSnake to bring down web servers. A Slowloris attack happens when an attacker makes incomplete HTTP requests with no intention of finishing them. Slowloris transmits HTTP headers for each request regularly to keep the computer network’s resources busy. This process is repeated until the server is unable to make any more connections. Attackers utilize this type of attack because it requires little bandwidth.

HTTP Flood – In an HTTP Flood attack, the attacker launches an attack on a single web server or application by using HTTP GET or POST requests. HTTP floods are a Layer 7 attack that does not employ faulty or faked packets. This form of attack is used by attackers since it requires less bandwidth than other assaults to knock the victim’s network offline.

Zero-Day Attacks — Zero-day attacks are those that make use of vulnerabilities that have not yet been detected. This is a catch-all phrase for potential future assaults. These sorts of attacks may be especially devastating since the victim has no means of preparing for them before they occur.

DDOS vs. DoS Attacks

What is the difference between a DoS assault and a DDoS attack?

A DoS attack is a type of denial of service assault in which a machine floods a server with TCP and UDP packets. A DDoS assault occurs when several systems launch DoS attacks on a single system. The targeted network is subsequently deluged with packets from all around the world.

All DDoS equals DoS, but not all DoS equals DDoS.

Denial of Service (DoS) and Distributed Denial of Service (DDoS) assaults are two of the most frightening dangers to modern businesses. Few types of attacks have the financial repercussions that a successful DoS assault does. According to security surveys, the cost of a DDoS assault is between $20,000 and $40,000 per hour. This is a staggering sum that may put even the most powerful companies under duress.

DDoS Attacks in Their Most Common Forms

DDoS assaults can take several forms, including:

What Causes DoS and DDoS Attacks

There are numerous sinister reasons an attacker would wish to take a firm offline, whether it be a DoS or DDoS assault. In this part, we’ll look at some of the most prevalent reasons organizations are targeted by DoS assaults. Typical explanations include:

Ransom – Extortion of a ransom is the most typical cause for DDoS assaults. After a successful assault, the attackers will demand a ransom to stop the attack and bring the network back up. It is not recommended to pay these ransoms, since there is no assurance that the business will be reopened.

Malicious Competitors — Another probable motive for DDoS assaults is malicious competitors seeking to shut down a firm. A rival might try to steal your customers by knocking down an enterprise’s network. This is said to be especially widespread in the online gambling community, where competitors may try to take one another offline to gain a competitive edge.

Hacktivism — In many circumstances, the reason for an assault will be personal and political rather than financial. It is not commonplace for hacktivist organizations to take down the government and corporate websites to demonstrate their displeasure. This can be done for any purpose that the attacker feels is significant, but it is most typically done for political reasons.

Trouble-making — Many attackers like causing problems for individual users and networks. It is no secret that cyber attackers find it fun to take down corporations. DDoS assaults provide a means for multiple attackers to troll people. Many people see these assaults as “victimless,” which is regrettable given how much money a successful attack can cost an institution.

Employee Dissatisfaction — Another prevalent cause of cyber assaults is dissatisfied workers or ex-employees. If the individual has a grudge against your organization, a DDoS assault might be an effective means for them to retaliate. While most workers manage grievances maturely, there is a minority that uses these assaults to harm a business with which they have personal concerns.

How to Protect Against DoS and DDoS Attacks

Even though distributed denial of service (DDoS) assaults is a persistent danger to modern companies, there are several actions you can take to defend yourself both before and after an attack. Before adopting a defense plan, it is critical to understand that you will not be able to block every DoS assault that comes your way. You will be able to mitigate the effects of a successful strike.

It comes down to three elements regarding minimizing the harm of incoming attacks:

Preventative Actions

Demonstrate DOS Attacks

Response to an Attack

Preventive measures, such as network monitoring, are designed to assist you in identifying assaults before they take your system offline and to act as a barrier against being attacked. Similarly, testing DoS assaults helps you to test your DoS defenses and optimize your overall approach. Your post-attack reaction will decide the extent of the damage caused by a DoS assault, and it is a plan for getting your organization back up and running after a successful attack.

Preventive Actions: Network Monitoring

Monitoring your network traffic is one of the most effective preventive measures you can take. Regular traffic monitoring will help you to detect indicators of an attack before the service goes down altogether. You’ll be able to act if you monitor your traffic and notice unexpected data traffic volumes or an unfamiliar IP address. This can mean the difference between getting taken offline and remaining online.

Most attackers will first test your network with a few packets before beginning a full-fledged attack. Monitoring your network traffic will help you to keep an eye out for these little signals and discover them early, allowing you to keep your service operational and prevent the expenses associated with unexpected downtime.

Demonstrating DoS Attacks

Unfortunately, you will not be able to defend against every DoS assault that comes your way. You may, however, ensure that you are ready if an assault occurs. Simulating DDoS attacks on your network is one of the most direct methods to do this. Simulating an attack allows you to evaluate your present preventive tactics and develop real-time preventative strategies that can save you a lot of money if a genuine assault occurs.

Plan for Post-Attack Reaction

If an assault is launched, you must have a plan in place to handle damage control. A well-thought-out strategy can be the difference between an inconvenient and a devastating attack. As part of your strategy, you should assign responsibilities to individuals on your team who will be accountable for reacting in the event of an attack. This involves developing customer assistance protocols so that consumers aren’t left hanging while you deal with technological issues.

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