Security teams are dealing with new digital threats on an almost daily basis. From malware and ransomware to highly sophisticated, AI-driven attacks, IT teams always have their hands full. But one specific type of attack, known as a denial of service attack or DoS attack, is a mainstay in many hackers’ repertoires. After a minor lull in 2018, Denial of Service patterns were identified within over 40% of 2019’s and 2020’s cybersecurity incidents, according to Verizon’s 2021 Data Breach Incident Report.
Investigating Modern DoS Attacks
Apart from viruses, DoS attacks are amongst the earliest online threats. They’re used to disrupt the service of an organization or an individual. While there are two distinct types of DoS attacks, including the standard denial of service and the distributed denial of service attack (DDoS attack), they share many similarities that are easily detectable by a trained and professional eye.
Understanding what separates these two is the first step to identifying and overcoming DoS and DDoS attacks. Gaining a basic familiarity requires knowing:
- The critical differences between DoS and DDoS attacks
- How to identify attacks while they’re occurring
The Different Types of Denial of Service Attacks
Although denial of service and distributed denial of service strikes both share many common traits—and the terms are often used interchangeably—they involve two different strategies. They also have distinct purposes within a hacker’s playbook:
- Standard DoS attacks – Generally carried out by a single machine, these attacks flood a target system with malicious traffic in an attempt to block any genuine web traffic.
- Smurf attacks – In these strikes, the hacker spoofs the targeted system’s Internet Protocol (IP) address and sends requests to various hosts. As the hosts attempt to respond all at once, the traffic generated eventually overloads the targeted system.
- SYN flood attacks – These attacks occur by facilitating a series of “incomplete handshakes” with a targeted server. Since they’re left incomplete and regarded as active, the port is considered occupied and unavailable to accommodate additional traffic.
- DDoS attacks – Very similar to standard DoS attacks, distributed denial of service attacks use multiple machines instead of a single source. The result is an attack that is much larger and more difficult to overcome.
Standard DoS Attacks
The standard DoS attack is a malicious strike that makes it difficult (or impossible) for legitimate users to access network resources. By filling a network with more traffic than it can handle, an ambitious hacker can easily overload a network with illegitimate requests. This makes it difficult or even impossible for genuine traffic to connect. Instead, legitimate users are greeted with an error message while the server continually processes the DoS traffic.
Denial of service attacks often target large-scale organizations and might affect software or hardware resources. When they occur, your organization’s chief information security officer (CISO) oversees response and remediation. If a virtual CISO (vCISO) is used, DoS attacks are their responsibility.
Common targets include:
- eCommerce storefronts
- Email servers
- Online banks
- Community message boards
- Social media
In some cases, individual users are the target of a DoS attack. These strikes are rarely arbitrary and generally serve as retaliation. However, unprompted and random DoS attacks do occur. Regardless of the scenario, DoS attacks can last for minutes, hours, days, or weeks.
Warning Signs of a DoS Attack
Several telltale signs can alert you to a DoS attack, some of which include:
- Slow network performance, especially when transferring data or accessing the internet
- Inability to access a specific website
- Inability to access the internet for any purpose
When a DoS attack has been identified, your security team and CISO or vCISO must initiate your organization’s established incident response protocols.
Also known as a distributed denial of service attack, these strikes utilize multiple machines to flood a target with even more illegitimate data. In most cases, hackers use hijacked systems to execute DDoS attacks. This minimizes the use of their personal resources, makes them more difficult to track, and results in a much larger attack overall.
Some hackers utilize botnets to execute their DDoS attacks. Websites rent these botnets, which include a series of compromised systems, to make it easier for hackers who lack the available resources or expertise to orchestrate the event independently.
Warning Signs of a DDoS Attack
Like standard denial of service attacks, your security team and CISO or vCISOs can spot DDoS attacks by looking for the telltale signs. These include:
- Large amounts of traffic from a specific IP address or range of addresses
- Suspicious traffic from identical devices or resources
- Unexplainable spikes in web traffic, particularly during certain timeframes
Overcoming DoS Attacks
Denial of service attacks are devastating to your organization’s operations and service delivery. While most DoS and DDoS attacks can be avoided with a combination of network firewalls and employee training, that’s often not enough to stop the most dedicated hackers.
To learn more about these attacks, how to prevent them, and the value of partnering with a vCISO to oversee your efforts, contact RSI Security today.