medobojafa
Code Fusion Specialist
Divine
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What is DoS Attack?
DOS is an attack used to deny legitimate users access to a resource such as accessing a website, network, emails, etc. or making it extremely slow. DoS is the acronym for Denial of Service. This type of attack is usually implemented by hitting the target resource such as a web server with too many requests at the same time. This results in the server failing to respond to all the requests. The effect of this can either be crashing the servers or slowing them down.
Cutting off some business from the internet can lead to significant loss of business or money. The internet and https://www.guru99.com/basic-computer-network.html power a lot of businesses. Some organizations such as payment gateways, e-commerce sites entirely depend on the internet to do business.
In this tutorial, we will introduce you to what denial of service attack is, how it is performed and how you can protect against such attacks.
Topics covered in this tutorial
There are two types of Dos attacks namely;
DoS Protection: Prevent an attack
An organization can adopt the following policy to protect itself against Denial of Service attacks.
We will assume you are using Windows for this exercise. We will also assume that you have at least two computers that are on the same network. DOS attacks are illegal on networks that you are not authorized to do so. This is why you will need to setup your own network for this exercise.
Open the command prompt on the target computer
Enter the command ipconfig. You will get results similar to the ones shown below
Flooding the target computer with data packets doesn’t have much effect on the victim. In order for the attack to be more effective, you should attack the target computer with pings from more than one computer.
The above attack can be used to attacker routers, web servers etc.
If you want to see the effects of the attack on the target computer, you can open the task manager and view the network activities.
You should be able to see the following results
DOS is an attack used to deny legitimate users access to a resource such as accessing a website, network, emails, etc. or making it extremely slow. DoS is the acronym for Denial of Service. This type of attack is usually implemented by hitting the target resource such as a web server with too many requests at the same time. This results in the server failing to respond to all the requests. The effect of this can either be crashing the servers or slowing them down.
Cutting off some business from the internet can lead to significant loss of business or money. The internet and https://www.guru99.com/basic-computer-network.html power a lot of businesses. Some organizations such as payment gateways, e-commerce sites entirely depend on the internet to do business.
In this tutorial, we will introduce you to what denial of service attack is, how it is performed and how you can protect against such attacks.
Topics covered in this tutorial
- Types of Dos Attacks
- How DoS attacks work
- DoS attack tools
- DoS Protection: Prevent an attack
- Hacking Activity: Ping of Death
- Hacking Activity: Launch a DOS attack
There are two types of Dos attacks namely;
- DoS– this type of attack is performed by a single host
- Distributed DoS– this type of attack is performed by a number of compromised machines that all target the same victim. It floods the network with data packets.
- Nemesy– this tool can be used to generate random packets. It works on windows. This tool can be downloaded from http://packetstormsecurity.com/files/25599/nemesy13.zip.html . Due to the nature of the program, if you have an antivirus, it will most likely be detected as a virus.
- Land and LaTierra– this tool can be used for IP spoofing and opening TCP connections
- Blast– this tool can be downloaded from http://www.opencomm.co.uk/products/blast/features.php
- Panther– this tool can be used to flood a victim’s network with UDP packets.
- Botnets– these are multitudes of compromised computers on the Internet that can be used to perform a distributed denial of service attack.
DoS Protection: Prevent an attack
An organization can adopt the following policy to protect itself against Denial of Service attacks.
- Attacks such as SYN flooding take advantage of bugs in the operating system. Installing security patches can help reduce the chances of such attacks.
- Intrusion detection systems can also be used to identify and even stop illegal activities
- Firewalls can be used to stop simple DoS attacks by blocking all traffic coming from an attacker by identifying his IP.
- Routers can be configured via the Access Control List to limit access to the network and drop suspected illegal traffic.
We will assume you are using Windows for this exercise. We will also assume that you have at least two computers that are on the same network. DOS attacks are illegal on networks that you are not authorized to do so. This is why you will need to setup your own network for this exercise.
Open the command prompt on the target computer
Enter the command ipconfig. You will get results similar to the ones shown below
- “ping” sends the data packets to the victim
- “10.128.131.108” is the IP address of the victim
- “-t” means the data packets should be sent until the program is stopped
- “-l” specifies the data load to be sent to the victim
Flooding the target computer with data packets doesn’t have much effect on the victim. In order for the attack to be more effective, you should attack the target computer with pings from more than one computer.
The above attack can be used to attacker routers, web servers etc.
If you want to see the effects of the attack on the target computer, you can open the task manager and view the network activities.
- Right click on the taskbar
- Select start task manager
- Click on the network tab
- You will get results similar to the following
- Download Nemesy from http://packetstormsecurity.com/files/25599/nemesy13.zip.html
- Unzip it and run the program Nemesy.exe
- You will get the following interface
- 0 as the number of packets means infinity. You can set it to the desired number if you do not want to send, infinity data packets
- The size field specifies the data bytes to be sent and the delay specifies the time interval in milliseconds.
You should be able to see the following results
- A denial of service attack’s intent is to deny legitimate users access to a resource such as a network, server etc.
- There are two types of attacks, denial of service and distributed denial of service.
- A denial of service attack can be carried out using SYN Flooding, Ping of Death, Teardrop, Smurf or buffer overflow
- Security patches for operating systems, router configuration, firewalls and intrusion detection systems can be used to protect against denial of service attacks.