Denial of Services Attacks

What is a Denial of Service Attack (DoS)?

A denial of service attack occurs when a malicious individual or element attempts or is successful at blocking access to a workstation, server, internal network, Internet, or other infrastructure services making those resources unavailable to one or multiple users.

The intent of a DDoS attack is to render the computing environment unusable for a period of time, thus interrupting normal personal or business operations or making the resources unusable.  In practical terms, it would be equivalent to people flooding a retail store rendering the day to day services unavailable to the legitimate consumer.

What types of DoS attacks exist?

1. Distributed Denial of Service Attack: This occurs when the perpetrator uses multiple IP addresses to access an environment causing the target to expend all of its resources processing the requests.
2. Advanced Persistent DoS Attack: These types of attacks occur when the perpetrator uses advanced computing techniques to barrage the target over an extended period of time. This type of attack is characterized by the perpetrator having (intelligence) foreknowledge of the environment and using tactical approaches to drain the target’s resources.
3. Denial of Service (as a service) Attack: These types of attacks are characterized by web-based interfaces that appear legitimate when using, but often result in the system accessing them expending all resources and rendering the device unusable.

How can I recognize a DoS attack?

Ultimately, the inability of a system or systems may be prime symptoms of a DoS attack.  However, a few of the key indicators may include:

1. Recognizable decrease in network performance
2. Inability to access a particular web site
3. Increase in the number of spam emails received
4. One-off or frequent disconnection of a wireless or wired internet connection
5. Long-term denial of access to the web or any internet services.