Distributed Denial-of-Service (DDoS), otherwise known as Distributed Denial-of-Service Attack, is a powerful form of cyber warfare. DDoS is a form of a distributed attack, which is made up of multiple online agents that simultaneously interfere with the target server. A DDoS is a strategic attack strategy in which the attacker or attackers make use of several forms of network activity in order to create confusion and eventually shut down or control the victim’s system.
This is done through a large number of carefully timed techniques such as downloading an unknown file types, malicious websites, and scanning the target computer for infected files and Trojans. These techniques can be executed in packets and can thus create a denial in the network. A Distributed Denial-of-Service attack can also be executed in a parallel network using different tools that are installed on the systems of the different attackers.
Distributed Denial-of-Service attacks can be delivered by attackers across the Internet. There are many reasons why a Distributed Denial-of-Service (DDoS) attack may be initiated. A DDoS occurs when a Distributed Denial-of-Service attack takes place. An attacker can initiate the attack either during normal working time, or at random.
The common techniques that enable attackers to bring down a target application or server are: flooding the target system with synchronized requests over a wide area network, timing a response from the target system so that it will exceed the maximum allowed time for a requested operation, sending multiple spoofed IP packets to the target system, and sending a crafted packet containing a virus inside.
There are two standard types of DDoS; Distributed Denial-of-Service (DDoS) and Application layer attacks. Distributed Denial-of-Service attacks can occur on the client side and are mostly executed against servers. Application layer attacks occur on the layers of the software stack, such as the network layer and the operating system. For an example, a common attack is the application layer exploit which attacks the Windows Service layer and allows attackers to bypass security restrictions and execute malicious code.
Application layer exploits are executed against Windows 2021, Windows NT, Windows XP, and Windows Vista. Some of these applications have been known to execute different types of DDoS attacks against different types of servers. For instance, the most famous attack against Windows server is the Remote Access Trojan (RAT). It can install itself on a victim machine and use different types of remote access tools to make DDoS attacks against different types of systems.
Distributed Denial-Of-Service attacks can be prevented if the victim has implemented proper countermeasures. The countermeasures usually block the unwanted or malicious network requests before being allowed through the network. This can be done with a simple blocklist. A blocklist allows a computer to be informed when it is being used for illegal activities. The purpose of the blocklist is to make the DDoS attacker avoid using that IP address in the future.
Distributed application layer attacks include buffer overflows and related logic attacks, cache hijacking, and related logic attacks. Buffer overflow allows an application to consume resources on a non-persistent storage for its own use. This consumes a scarce resource and makes the system vulnerable to malicious attacks. Buffer overflow attacks can be prevented by preventing programs from using temporary files. It is also important to update applications regularly.
Common DDoS attacks types
- ICMP (Ping) Flood.
- SYN Flood.
- Ping of Death.
- Slowloris.
- NTP Amplification.
- HTTP Flood.
- Zero-day DDoS Attacks.
- Volume Based Attacks
As mentioned above, the common ways to defeat application layer attacks include denial-of-service (DDoS), traffic shaping, and traffic normalization. Traffic normalization prevents a DDoS by overwhelming a single system with too much traffic, forcing the attackers to choose between overusing that resource or risking server failure. DDoS mitigation is also possible through various techniques such as overload detection. If a site is overloaded, the probability that an attack will occur is reduced.
Distributed protocol attacks includes the use of spoofing to send repeated packets of the incorrect data, or of the wrong kind. It can lead to increased server downtime, and consequently increase the likelihood of a server attack. In many cases, a spoof will cause an unsuspecting victim to connect to the spoofed source instead of the intended victim. Some of the common spoofing techniques include ICMP Echo Tracing, Destination Server spoofing, and Neighbor Discovery.