Attackers use various hacking techniques to compromise a website or computer. The most common are Trojan horses, denial of service, unprotected Windows shares, mobile code, cross-site scripting, and packet sniffing. This document will discuss in detail how attackers use these hacking techniques to compromise a system, how attackers collect information from a victim via their email communication, and how to prevent attacks. Trojan horse programs are a common way for intruders to trick a user. when installing backdoor programs. According to Armor2net, these programs can give intruders easy access to a computer without the user's knowledge, change system configurations, or infect the computer with a computer virus. These backdoor or remote administration programs are also known as social engineering. In fact, hackers usually use BackOrifice, Netbus, and SubSeven to gain remote access to users' computers. Once installed, these programs will allow them to access and control computers. Denial of Service (DoS) is another technique frequently used by hackers. The DoS attack causes the user's computer to crash or become so busy processing data that the computer is unable to use it. According to Armor2net, it is important to note that in addition to being the target of a DoS attack, it is possible for attackers to also use the computer to participate in another DoS attack on another system. In fact, this technique is called a Distributed Denial-of-Service (DDoS) attack. Attackers install a backdoor program that runs on the compromised computer and wait for further instructions. When a number of backdoors are running on different computers, a single "handler" can instruct all of these backdoors to launch a DoS attack... middle of paper...understand the concepts behind client-side attacks and how they connect to coding. This will help to better protect its application systems (Riden, 2008). Being able to use existing client-side exploits to compromise the lab's victim machines will help a software developer better understand attacks and be able to prevent them. References Riden, Jamie. August 2008. Client-side attacks. Retrieved April 21, 2014, from http://www.honeynet.org/node/157Curphey, M. & Groves, D. 2008. OWASP Testing Guide: How to Value the Real Risk? Page 325-333.Armor2net. “The most common methods used by hackers”. Retrieved 5/3/2014 from http://www.armor2net.com/knowledge/hackers_methods.htmCombined Fix. “Three Techniques Hackers Use to Break Into Accounts.” Retrieved 2/5/2014 from http://www.combofix.org/tre-techniques-used-by-hackers-to-break-into-accounts.php