Have you heard about DOS or denial-of-service attack? It is an attempt to make a pc resource unavailable to its users. Although the means to hold out, motives for, and targets of a DoS attack might vary, it usually consists of the concerted efforts of an individual or people to stop an internet web site or service from functioning efficiently or at all, indefinitely or temporarily.
Resources targeted in a DoS attack are often a particular pc, a service or port on the targeted system, a whole network, a component of a given network any system component. DoS attacks can also target human-system communications, or human-response systems.<!–more–>
DoS attacks may target tangible system resources, like configuration data, state information, and computational resources. Moreover, a DoS attack are often designed to execute malware that maxes out the processor, trigger errors in machine microcode, preventing usage, or arranging of instructions, forcing the pc into an unstable state, exploit OS vulnerabilities to sap system resources, crash the OS altogether.
DoS attacks are inexpensive and are tough to counter without the proper tools. This makes them very popular among the people skilled with technical knowledge. Also the Dos services are offered for many websites starting from $50. These services are becoming more and more sophisticated, and may effectively exploit application vulnerabilities and also evade detection by firewalls.
The most common form of DoS attack is just to send more traffic to a network address than the programmers who planned its information buffers anticipated someone might send. The attacker may also be aware that the target system features a weakness that can be exploited or the attacker may simply attempt the attack in case it would work.
A few of the known attacks based on the buffer characteristics of a program or system include:
- Sending e-mail messages attachments with file names containing 256-characte to Netscape and Microsoft mail programs.
- Sending large ICMP (Internet Control Message Protocol).
- A message with “From” address larger than 256 characters are sending to a user of the Pine e-mail processor.
There are many symptoms of denial-of-service attacks. Now let us have a look at these:
- Unusual slow network performance
- Unavailability of a website
- Inability of accessing any website
- There is a large increase in the number spam emails
DoS attacks may also cause the issue in the network ‘branches’ around the actual system being attacked. An example of this is the bandwidth of the internet and the LAN may also consumed by an attack, compromising not only the suggested system. But also the entire network. If the attack takes place on a massive scale, then the whole regions of web connectivity are often compromised without the knowledge of the attackers or intent by incorrectly designed or filmsy network infrastructure equipment.0