The term “DoS” or Denial of Service attacks refers to incidents that make systems on computer networks temporarily inaccessible and unusable. DoS attacks could occur due to certain activities of network administrators or users, but usually occur due to the acts of malicious individuals or hackers. These attacks could cost businesses money and time while their services and resources are inaccessible. When studying for the CompTIA Network+ N10 007 certification exam, note that 20% of the exam covers network security, which includes different network threats such as DoS attacks.
What Exactly is a DoS Attack?
DoS attacks happen when legitimate network users find themselves incapable of accessing information of devices, systems, and network devices because of the actions of hackers. In general, affected service usually includes email accounts, online accounts (usually those financial), websites, and other services that depend on the compromised network or computer system. Hackers accomplish DoS attacks by flooding a target network or host with traffic that the target can’t possibly accommodate, which in turn leads to it crashing and preventing legitimate users access to its network resources.
Examples of DoS Attacks
The most infamous DoS attack is the Ping of Death that functions by creating and transmitting network messages that lead to all sorts of issues for the target networks that receive them. It’s some type of buffer overflow attack capable of overrunning the target host’s memory and disrupt its programming logic by sending larger pieces of data that the host could process. Other common kinds of DoS attacks include the following:
- Modifying or breaking permissions and authorization logic to stop users from logging in to the compromised system;
- Overloading a target system’s CPU remotely to prevent the processing of valid requests;
- Flooding the target system with useless activities to prevent genuine traffic from getting through; and
- Interfering or deleting certain critical services or applications to thwart their normal operations.
How to Identify a DoS Attack
These red flags could signal a DoS attack:
- Failure to access any site;
- Failure to access a certain site; or
- Unusually and significantly slow performance of the target system.
The ideal method for detecting and identifying DoS attacks is by monitoring and analyzing the network traffic through an intrusion detection system or firewall.
How to Prevent a DoS Attack
Although there’s no surefire way to prevent a DoS attack from compromising a network or computer system, administrators could take specific steps to try and mitigate the potential impact of a DoS attack. You could enroll in a protection service specifically for DoS attacks that would help detect unusual traffic flows and reroute that traffic somewhere else. It would likewise filter out the DoS traffic and only send clean traffic your way. You could also make a disaster recovery strategy to help ensure efficient and successful mitigation and recovery should you experience a DoS attack. Additionally, make sure that all devices that connect to the Internet are as secure as possible to prevent them from being attacked.