There are four primary classes of attacks.
Reconnaissance is the unauthorized discovery and mapping of systems, services, or vulnerabilities. It is also known as information gathering and, in most cases, it precedes another type of attack. Reconnaissance is similar to a thief casing a neighborhood for vulnerable homes to break into, such as an unoccupied residence, easy-to-open doors, or open windows.
System access is the ability for an intruder to gain access to a device for which the intruder does not have an account or a password. Entering or accessing systems usually involves running a hack, script, or tool that exploits a known vulnerability of the system or application being attacked
Denial of service (DoS) is when an attacker disables or corrupts networks, systems, or services with the intent to deny services to intended users. DoS attacks involve either crashing the system or slowing it down to the point that it is unusable. But DoS can also be as simple as deleting or corrupting information. In most cases, performing the attack involves simply running a hack or script. For these reasons, DoS attacks are the most feared.
ex : type of attack is characterized by a flood of packets that are requesting a TCP connection to a server.
Worms, Viruses, and Trojan Horses. Malicious software can be inserted onto a host to damage or corrupt a system, replicate itself, or deny access to networks, systems, or services. Common names for this type of software are worms, viruses, and Trojan horses.
link : CNAP, Exploration 4
