7 Best Free Dos Attacking Tools

Free Dos Attacking Tools

The denial of service or Dos is one of the most powerful attacks to take down a went or a network. Before I proceed further I want to make it clear that the DOS attack and DOS operating system are two different things. In this article whenever I say DOS, It means Denial Of Service.

DOS attack is one of the most powerful attacks. If you look at the history of cyber attacks of this decade, you will see how the DOS attack has cost millions to different organizations. In the DOS attack, an attacker tried to flood a service by sending fake requests continuously. In a few seconds or minutes, these requests fully engage the server making it unavailable for legitimate users.

There is another thing called DDOS or Distributed Denial of Service Attack. In this attack, multiple attackers flood a server with fake requests. Because attackers are distributed across different regions, this is called Distributed Denial of Service Attack. Distributed Denial of Service Attack is used on big servers that could handle a high number of requests. So, performing an attack from a single system cannot harm it.

I am not going into many details of the DOS attack. I have an old article about the DOS attack. Read that to know about it in detail. This article is about the best free DOs attacking tools. By using any of these DOS tools, you can perform the DOS attack on a server or website.

This article is just for educational purposes. You can use these tools to learn and see how DOS attack works. Do not try these DOS tools against any website or big organization. They can easily trace back your IP and take a legal against you. We will not be responsible for any harm you do to yourself.
Differnet countries have different publishment, but no country is soft on cyber attackers. So, use these tools only on your websites or on requests where you have permission to use.

Best Dos Attacking Tools

1. LOIC (Low Orbit Ion Canon)

LOIC is the best and one of the most popular DOS attacking tools available on the internet. it can be used to perform a DOS attack on a smalls server by sending UDP, TCP, or HTTP requests. You only need the IP address or URL of the server to perform the DOs attack against it. It is really easy to understand and use. Look at the screenshot of the main screen. Nothing is complicated.

LOIC : DOS attacking tool

LOIC can also be used to perform a DDOS attack. Multiple people can use this tool against a server or website to perform DDOS. The HIVEMIND mode lets the primary attacker take control of remote LOIC systems while performing the DDOS attack.

It is also interesting to note that LOIC was the weapon of popular hackers group Anonymous who used it against several big organizations in the past.

LOIC cannot hide your IP. If you are planning to download and use it against someone, make sure you know how to use proxy to keep your IP hidden. Otherwise, you will be in big trouble.

This tool can easily be detected by IDS/IPS/AV and it also cannot attack multiple targets at one time.


2. HOIC (High Orbit ION cannon)

HOIC is the successor of LOIC. It is the successor, so more powerful. It is also an opensource DoS tool capable of performing a DOS attack on 256 targets simultaneously. It also generates a large number of junk HTTP requests to overload the application server.

HOIC : DOS attacking tool

It also has a simple GUI making it easy to use. You can enter the target, fire mode, and perform attacks. You can also use the Booster to increase the power of the tool. You can also launch a DDOS attack by using manual co-ordination.

If I talk about the limitations, this tool cannot generate TCP and UDP floods. It can only be used against the HTTP servers. The source of the attack can also easily be detected and blocked.

This tool is seriously powerful. If you are new into hacking, avoid using this one without understanding DOS. It can be dangerous and you can be in trouble.


3. HULK (HTTP Unbearable Load King)

HULK stands for HTTP Unbearable Load King. So, it is clear that this DOS attack tool can perform DOS attacks against HTTP web servers. It generates a unique request for each and every generated request to flood a web server with fake requests and take it down. This tool also uses several other techniques to avoid attack detection via a firewall. These include the random use of user agents, referrer forgery, bypass caching engines and more. So, it hits the server’s direct resource pool and can take it down within a minute.

This is a python based script, which means no GUI. You need to install python in your system first before the use. When your system is ready to run python scripts, you can open the terminal and navigate to the Hulk folder. Then use the following commands.

sudo python hulk.py 
sudo python hulk.py http://IPaddress:Port

This tool is difficult to detect as it has the capability to hide/obfuscate source. It also comes with forging capabilities for various fields in the web request. Proper traffic analysis is needed to detect and block the attack.



RUDY or R-U-Dead-Yet is an HTTP post method DOS attack tool to perform a DOS attack on web pages having form. It automatically detects the form on a given URL and lets users select what form (in case of multiple forms) and fields should be used for a POST-based DOS attack. This tool Sens legitimate HTTP POST request with a long ‘content-length’ header field. It prevents the server from closing the connection. Then it starts injecting the form at a slow rate. In a few seconds, the server becomes unavailable for legitimate requests.

This tool supports SOCKS proxies and session persistence using cookies. It is only HTTP based) DOS attacking tool and the website must have a form to use this tool. It takes time because the rate of attack is slow. This tool can also be detected easily due to abnormal traffic.


5. Slowloris

Slowloris is also a good DOS attacking tool. It uses incomplete HTTP GET requests to flood a web server. While the webserver waits for the request to complete after allocating the resources, there are multiple Parallel threads of incomplete HTTP GET requests. Thus the resources of the web server are exhausted.

This script is also available in NMAP for testing the response of the webserver. It works only on the HTTP layer and is slow. So, it can be detected as abnormal traffic and blocked.

You can PIP to install and then use it. Use the following commands.

sudo pip3 install slowloris
slowloris example.com



DDOSIM is also the layer-7 DOS attacking tool written on C++. It simulates several zombie hosts with random IP addresses and creates full TCP connections to the target server. Then it starts listening to the HTTP port. It can perform Application layer DDOS attacks and TCP based attacks. The tool uses random source IP addresses. SO, it pretends to be a botnet or DDOS attack while it is actually from a single system.


7. PyLoris

PyLoris is basically a penetration testing tool to find vulnerability in servers that could lead to DoS attacks. The tool can utilize SOCKS proxies and SSL connections while targeting direct protocols such as HTTP, FTP, SMTP, IMAP, and Telnet. It opens full TCP connections and keeps them open for as long as possible.

PyLoris: Dos Attacking Tools

This tool can be used to test poorly managed connection strategy and High memory allocation per connection. It has a GUI that lets you enter the host and port along with the behaviour of the attack.


Final Words

There are so many other DOS attack tools but these are enough for leaning purposes. DOS attack looks simple but in reality, it is dangerous and can cost millions to an organization. Availability of free and easy to use DOS attacking tools make performing DOS attack easy. Even a newbie or kid can perform a DOS attack. So, it is important for organizations to understand the risk and have a proper mechanism to protect their servers or websites. Organizations need to have a proper firewall and IDS to detect and disable these kinds of attacks. If you are learning hacking, it is really important for you to understand how the DOS attack works and what kinds of tools are used to perform these attacks. Then you can easily understand how to detect and block these attacks.

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Deepanker Verma is the founder of Techlomedia. He is a tech blogger, developer and gadget freak.

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