Denial-of-service (DoS) is a type of cyber-attack that is designed to disrupt, paralyze, or crash a website or network. The idea behind a DoS attack is to make the system unresponsive or unavailable to its intended users by overwhelming the resources of the targeted server or network with a flood of traffic. The attack usually involves hackers flooding the victim’s network with a massive volume of fake traffic or commands that impact the availability of legitimate users.
DoS attacks have become more common over the years, and many organizations, businesses, and governments have been victims of these attacks. Hackers use various techniques to launch a DoS attack, and the goal is typically to cause inconvenience or damage by bringing down a service or website.
Techniques used in DoS attacks
There are different techniques used in DoS attacks, and each has its unique way of causing harm to the targeted system. Some of the commonly used DoS attack methods include:
1. Ping Flood
Ping flood is one of the most popular DoS attack techniques. The attack involves sending a massive number of ping requests to a server, which leads to the server becoming overwhelmed and unable to serve legitimate users. Pings are used to check if a server or network is online and to measure its response time. Attackers take advantage of this by flooding the server with pings, which ultimately overloads the system.
2. Botnets
Botnets are a network of infected machines that are controlled by a central server. These machines are used to launch coordinated and massive-scale attacks on servers and networks. The machines that make up a botnet are usually compromised through malware or phishing attacks. When a botnet is activated, the infected machines will start sending a flood of traffic to the targeted server, ultimately overwhelming and knocking down the network.
3. SYN Flood
A SYN flood attack is a type of network-based attack that exploits vulnerabilities in the TCP/IP protocol. The attack involves sending a large number of SYN requests to the server in quick succession, which leads to the server becoming overwhelmed and unable to process legitimate traffic. The attack is prevalent in web servers, as web servers typically handle a large number of connections at once.
Real-life examples of DoS attacks
DoS attacks have become a common occurrence over the past years, and many individuals and organizations have been targeted. Here are some real-life examples of DoS attacks:
1. GitHub
In 2018, GitHub, a popular code-sharing platform, was hit by a massive DoS attack that lasted for several days. The attack was carried out by using a high-volume Memcached amplification attack that overwhelmed the targeted servers distributing junk traffic at such a high volume that GitHubs servers became overloaded and inaccessible to normal traffic.
2. PlayStation Network
PlayStation experienced a series of DoS attacks in 2014 that led to a major disruption of its gaming network. The attackers claimed that the motive behind the attack was to protest against the company’s Christmas tradition of releasing a new game every year. As a result of the attack, the PlayStation network was unavailable for several days, causing a significant inconvenience to its users.
3. BBC
The BBC website was hit by a massive DoS attack in December 2015. The attack was launched by a hacker group that claimed to be affiliated with Anonymous. As a result of the attack, the website became briefly unavailable to its users.
Preventing DoS attacks
To protect against DoS attacks, organizations should take precautionary measures to prevent such attacks from happening. Here are some preventive measures that organizations can employ:
1. Use firewalls
Firewalls are designed to protect against unauthorized access to a network or device. They can help detect and block traffic that is part of a DoS attack. Firewalls can also be used to limit the number of connections a server can receive from a single IP address, which can help prevent malicious traffic from overloading the server.
2. Network monitoring
Organizations should have effective network monitoring tools that can detect unusual traffic patterns and block any malicious traffic to prevent DoS attacks. The monitoring system should also be able to alert network administrators of any potential DoS attacks so they can take countermeasures.
3. Limit the number of requests from a single IP address
Limiting the number of requests coming from a single IP address can prevent an attacker from using a botnet to launch a DoS attack. The limitation can be configured to only allow a certain number of connections from a single IP address within a particular time frame.
Conclusion
In summary, a DoS attack can be detrimental to an organization, business, or individual. The attack is usually carried out by flooding a server with fake traffic or commands, which ultimately leads to the server becoming overloaded and unable to serve legitimate users. Organizations should take precautionary measures like using firewalls, network monitoring, and limiting the number of requests from single IP addresses to protect against such attacks. In conclusion, DoS attacks are a serious threat to cybersecurity, and effective measures must be employed to prevent them from happening.
