Security Threats

There are various types of threats to the above discussed most prominent elements. Some of the common threats to network security are as follows:

i. Denial-of-Service (DoS) attack: DoS attack aims to entirely consume network bandwidth and system resources by creating a large volume of network traffic. This makes it impossible for genuine users to use the resources which were meant for them.

ii. Distributed Denial of Service (DDoS) attack: DDoS attacks are a variant of DoS attacks in which an attacker simultaneously uses two or more machines to execute a DoS attack, to make the attack more powerful.

iii. Botnet: A botnet is a huge amount of devices linked to the Internet, each of which is infected by bots. A bot is a malware that allows an attacker to take control of a system. A bot is distributed in a variety of ways such as e-mail attachment which is unknowingly downloaded by the users. In this type of attack, an enormous number of computer systems perform their actions under the control of a single attacker.

iv. Payload Mutation: In this type of attack malicious packet payload is modified, but it is semantically same as original packet and looks very different from attack signatures. As it appears different from attack signatures, it can remain undetected by security measures.

v. SQL Injection attack: In this attack a part of malicious SQL query is inserted into web applications via the variables used by these web applications. These applications then send malicious queries to the database server by which an attacker can read, insert, delete or update database contents.

vi. User to Root Attack (U2R): In this type of attack, the invader somehow login as genuine user account by sniffing password and try to exploit certain susceptibility to obtain root access to the system.

vii. Remote to Local Attack (R2L): This attack happens when the invader who is not a legitimate user of the machine but by exploiting some weakness to gain access to local device and sends packets to other machines in the network.

viii. Probe Attack: In this type of attack, the invader attempts to collect information of the network for the purpose of evading its security controls.