The computer networks are based on free circulation of the information; they are built so to facilitate the users' access and to be very wide open to the information process. Attacks pose a serious security threat to a network environment. Once with the networks' connection to Internet or to other external computer networks, the aggression risks grow very much.

This paper constructed on the following bricks:-

1.      Abstract

2.      Introduction to New Attack Models

3.      What is an Attack?

4.      Purpose of launching attacks

5.      Types of Attacks

6.      Phishing

7.      Zombie computers and Bonnets

a.       Spyware

b.      Adware

c.       E- mail Spam

d.      Click Fraud

e.       Fast Flux

f.       Scare ware

8.      Cross Site Request Forgery

9.      Hardware Loss and Residual Data Fragments

10.  Application Layer Attack

a.       FTP related attacks

b.      SMTP related attacks

11.  Distributed Denial of service

a.       Bandwidth Depletion Attack

b.      Resource Depletion Attack

12.  Password Guessing Attacks

a.       Brute-force Attacks.

b.      Dictionary Attacks.

13.  Advanced Persistent Threats

14.  Unauthorized Access

a.       Internal Hacking

b.      External Hacking

15.  Viruses and Worms

16.  Trojan Horses

17.  Network Eavesdropping

18.  Prevention Methods

19.  Appendix

20.  References

In this paper we intend to present few types of network attacks which are common and pose a serious threat to the network systems along with certain measures or steps which should be necessarily taken in order to keep the networking computers secure from vulnerable attacks or intrusions and helps in securing the information.