How to Tell the Difference Between a DOS and a DDOS Attack

DoS and DDOS attacks are cyberattacks that deprive customers and employees of your services. Understanding these attacks and taking preemptive measures to thwart them is essential.

A buffer overflow attack is one of the most common types of DoS attack. It uses misconfigured network devices to flood an address with traffic, shutting it down.

The Attacker Sends a Bundle of Harmful Data

DoS attacks involve cyber attackers attempting to overwhelm a network or server with fraudulent traffic. The attacks can cripple the targeted server and prevent it from responding to legitimate requests, which can cause a website, online platform, or application to crash for days or weeks. It can result in a loss of business, a drop in user satisfaction, and a general disruption to normal operations.

Hackers use a variety of methods to execute DOS vs DDOS attacks. It is challenging for the victim to identify the problem’s origin because they frequently utilize a collection of hijacked devices known as bots to launch an attack from several locations.

It allows an attacker to mask their true identity and make it more difficult for the targeted system to recover from the attack. It also increases the attack magnitude, as each bot can add an exponential amount of attack power.

There are many types of DoS attacks, but some of the most common include buffer overflow attacks, ICMP floods, and teardrop attacks. During a buffer overflow attack, the cyber attacker overloads the target system with massive spam data packets that consume its resources. The server can’t handle the extra work and shuts down.

During an ICMP flood or Ping of Death attack, the cyber attacker uses misconfigured network devices to send spoof packets to ping every network device in a targeted network. It bogs down the network and uses up its available resources, which makes it impossible for actual users to connect to the service.

A teardrop attack is similar to the ICMP flood, except the cyber attacker sends altered data packets to the network that the server can’t reassemble. It wastes the server’s resources and causes it to shut down, stopping other network devices from accessing its services.

While DoS attacks are relatively simple to execute, they’re also convenient and cost organizations thousands of dollars annually in downtime and lost revenue. That makes them one of the most pervasive cybersecurity threats modern businesses must face.

The Attacker Floods the Target

A DoS attack is one of the most common cyberattacks businesses and individuals face. It deprives the attacked website, application, or server of the resources to be functional and available to legitimate users. Customers may become dissatisfied, there may be a loss in sales, and reputational harm may result.

An attacker floods a targeted system with traffic during this attack and saturates its open ports. It forces the system offline and makes accessing the website or application impossible. It may also result in data corruption and misdirection of network packets.

The attacker can use various methods, such as a SYN attack or a ping of death attack. In a SYN attack, an attacker sends multiple connections to the target server but fails to complete the three-way handshake. It saturates all available ports and prevents the server from processing legitimate requests.

In a ping-of-death attack, the attacker manipulates how length and fragmentation offset fields in sequential Internet Protocol (IP) packets overlap to confuse the attacked host. This results in the attacked system being unable to reassemble the packets, leading to a crash correctly. A denial-of-service attack can exploit the Transmission Control Protocol/User Datagram Protocol (TCP/UDP) layer.

A DDOS assault is comparable to a DoS attack in that it floods the target with traffic using numerous systems and Internet connections. It can be difficult for the attacked system to handle, and it is nearly impossible to identify the attacker’s origin because of its scale.

This type of attack is often conducted using a botnet, an extensive network of computers, and other devices infected with malware and controlled by an attacker remotely. The attacker can then command the bots to send a coordinated barrage of meaningless online requests to the target website or network, causing it to become overwhelmed and unavailable to its legitimate users.

Neither DOS vs DDOS attacks are good for business, but they can be avoided with careful network monitoring and good security practices. Familiarizing yourself with the different types of attacks can help you minimize their impact.

The Attacker Creates a Botnet

Hackers often use bots to execute DDoS attacks. The bots are computers that have been infected with malware. The hacker will either lure victims into making a drive-by download or exploit Web browser vulnerabilities. Once the malicious software is downloaded, it will install modules that allow it to be commanded and controlled by the attacker. The hacker will then connect the infected computer to a server that is known as a command and control (C&C) server. It allows the infected system to receive instructions from the C&C server and perform cyber attacks remotely.

The infected systems that the attacker controls are also known as slave computers. Once the bots are connected to the C&C server, they can be commanded to attack a network or specific servers and applications. The attack aims to overwhelm a website or network with traffic so that it can’t handle the volume and will be taken offline.

Because the attacker will employ several machines in the botnet to initiate the attack, a DDoS attack is more challenging to thwart than a DoS attack. A DDoS attack can be much more sophisticated than a DoS attack because it will be harder to tell where the attack is coming from.

For example, a SYN flood attack works by opening numerous connections to the target and never sending an ACK to close them. It will tax the victim’s server resources and cause it to become unresponsive to legitimate traffic.

Another type of DDoS attack is a UDP flood attack. These attacks flood a target’s network devices with ICMP echo requests or ping packets. These packets eat up all the available bandwidth, preventing other devices in the network from connecting to the server.

Cybercriminals have many nefarious reasons for using DDoS attacks. Some will launch them to take competitors off the Internet and steal their customers. Others will launch them out of revenge or to express political or ideological opinions. Hacktivists have been known to use DDoS attacks to put government or enterprise websites offline to mark their opposition.

The Attacker Makes the Target Unresponsive

DoS attacks can take a business or website offline for days or weeks, costing the victim thousands of lost revenue annually. This loss is exacerbated when a customer or employee can’t access the necessary information. Whether for financial gain or to tarnish their business reputation, cybercriminals use DoS attacks to wreak havoc on the people they target.

One way they do this is to flood network servers with junk requests that consume their available bandwidth. These service requests are illegitimate and often mislead the server with fabricated return addresses. Additionally, they may exploit vulnerabilities in the server software to craft special requests that eat up CPU resources.

Another way a cyber attacker makes the target unresponsive is by using a UDP (User Datagram Protocol) flood attack. This attack involves the attacker sending many UDP packets to random ports on the target server. Because the target system can’t process these packets, it sends “Destination Unreachable” messages back to the attacker. The attack continues to happen until the server is completely overwhelmed.

Lastly, an attacker can use a fragmentation attack to put the targeted network offline. This attack involves sending the compromised network data packets that have been manipulated to be too large to reassemble in bulk by the servers. It causes the server to be overwhelmed with unassembled data and causes the target network to become unresponsive.

The good news is that there are ways to avoid DoS and DDOS attacks. You can evaluate your security settings to minimize the accessibility of others to your information, and you can follow best practices to manage unwanted traffic (see Good Security Habits). In addition, implementing a firewall or IDS/IPS is essential to help filter out malicious activity.

Regardless of the reason behind an attack, business owners and individuals must understand the difference between DoS and DDOS attacks. While both attacks can damage businesses and individuals, a DDOS attack is a multiplied version of the original DoS attack. The more network devices an attacker targets with a DDoS attack, the more extensive the potential damage.