Denial of service (DOS) is a network security attack, in which, the hacker makes the system or data unavailable to someone who needs it.
Denial of service is of various types :
- Browser Redirection –
This happens when you are trying to reach a webpage, however, another page with a different URL opens. You can view only the directed page and are unable to view the contents of the original page. This is because the hacker has redirected the original page to a different page.
- Closing Connections –
After closing the connection, there can be no communication between the sender(server) and the receiver(client). The hacker closes the open connection and prevents the user from accessing resources.
- Data Destruction –
This is when the hacker destroys the resource so that it becomes unavailable. He might delete the resources, erase, wipe, overwrite or drop tables for data destruction.
- Resource Exhaustion –
This is when the hacker repeatedly requests access for a resource and eventually overloads the web application. The application slows down and finally crashes. In this case the user is unable to get access to the webpage.